Also affects Ideapad 3 15AB7 Ryzen 5825. Kubuntu 23.10 for all Kernels up to linux-next.

In all cases, secure boot on or off, MoK enabled or not and fTPM on/off give the same result. fTPM reading is abnormal.

$ sudo dmesg | grep fTPM
[    0.341408] tpm tpm0: AMD fTPM version 0x3004e00020005 causes system stutter; hwrng disabled

$ mokutil --sb
SecureBoot enabled
SecureBoot validation is disabled in shim

mokutil --sb
SecureBoot disabled
sudo dmesg | grep fTPM
no reading

Here's the x.509 error:

$ journalctl -b -1

...cut here...
-X.509 Boot/restart/all Kernels/all cases

23:51:34 mm systemd[1]: Stopped user-runtime-dir@1000.service - User Runtime Directory /run/user/1000.
May 03 23:51:34 mm systemd[1]: Removed slice user-1000.slice - User Slice of UID 1000.
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v1): a8d54bbb3825cfb94fa13c9f8a594a195c107b8d'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v2): 4cf046892d6fd3c9a5b03f98d845f90851dc6a8c'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v3): 100437bb6de6e469b581e61cd66bce3ef4ed53af'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (Ubuntu Core 2019): c1d57b8f6b743f23ee41f4f7ee292f06eecadfb9'
May 03 23:51:19 mm kernel: zswap: loaded using pool lzo/zbud
May 03 23:51:19 mm kernel: Key type .fscrypt registered
May 03 23:51:19 mm kernel: Key type fscrypt-provisioning registered
May 03 23:51:19 mm kernel: Key type trusted registered
May 03 23:51:19 mm kernel: Key type encrypted registered
May 03 23:51:19 mm kernel: AppArmor: AppArmor sha1 policy hashing enabled
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert 'Lenovo UEFI CA 2014: 4b91a68732eaefdd2c8ffffc6b027ec3449e9c8f'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Problem loading X.509 certificate -65
May 03 23:51:19 mm kernel: fbcon: Taking over console
May 03 23:51:19 mm kernel: integrity: Error adding keys to platform keyring UEFI:db
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: Console: switching to colour frame buffer device 240x67
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert ': 8129c1e0865297b1435ad4a47e4f424e'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: blacklist: Loading compiled-in revocation X.509 certificates
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing: 61482aa2830d0ab2ad5af10b7250da9033ddcef0'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2017): 242ade75ac4a15e50d50c84b0d45ff3eae707a03'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (ESM 2018): 365188c1d374d6b07c3c8f240f8ef722433d6a8b'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2019): c0746fd6c5da3ae827864651ad66ae47fe24b3e8'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v1): a8d54bbb3825cfb94fa13c9f8a594a195c107b8d'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v2): 4cf046892d6fd3c9a5b03f98d845f90851dc6a8c'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v3): 100437bb6de6e469b581e61cd66bce3ef4ed53af'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (Ubuntu Core 2019): c1d57b8f6b743f23ee41f4f7ee292f06eecadfb9'
May 03 23:51:19 mm kernel: zswap: loaded using pool lzo/zbud
May 03 23:51:19 mm kernel: Key type .fscrypt registered
May 03 23:51:19 mm kernel: Key type fscrypt-provisioning registered
May 03 23:51:19 mm kernel: Key type trusted registered
May 03 23:51:19 mm kernel: Key type encrypted registered
May 03 23:51:19 mm kernel: AppArmor: AppArmor sha1 policy hashing enabled
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert 'Lenovo UEFI CA 2014: 4b91a68732eaefdd2c8ffffc6b027ec3449e9c8f'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Problem loading X.509 certificate -65
May 03 23:51:19 mm kernel: fbcon: Taking over console
May 03 23:51:19 mm kernel: integrity: Error adding keys to platform keyring UEFI:db
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: Console: switching to colour frame buffer device 240x67
May 03 23:51:19 mm kernel: Loading compiled-in X.509 certificates
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Build time autogenerated kernel key: 1fc0e865c21818e2f5cce3868a567b58070b6c0d'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Live Patch Signing: 14df34d1a87cf37625abec039ef2bf521249b969'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Kernel Module Signing: 88f752e560a1e0737e31163a466ad7b70a850c19'
May 03 23:51:19 mm kernel: blacklist: Loading compiled-in revocation X.509 certificates
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing: 61482aa2830d0ab2ad5af10b7250da9033ddcef0'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2017): 242ade75ac4a15e50d50c84b0d45ff3eae707a03'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (ESM 2018): 365188c1d374d6b07c3c8f240f8ef722433d6a8b'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2019): c0746fd6c5da3ae827864651ad66ae47fe24b3e8'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v1): a8d54bbb3825cfb94fa13c9f8a594a195c107b8d'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v2): 4cf046892d6fd3c9a5b03f98d845f90851dc6a8c'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (2021 v3): 100437bb6de6e469b581e61cd66bce3ef4ed53af'
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Canonical Ltd. Secure Boot Signing (Ubuntu Core 2019): c1d57b8f6b743f23ee41f4f7ee292f06eecadfb9'
May 03 23:51:19 mm kernel: zswap: loaded using pool lzo/zbud
May 03 23:51:19 mm kernel: Key type .fscrypt registered
May 03 23:51:19 mm kernel: Key type fscrypt-provisioning registered
May 03 23:51:19 mm kernel: Key type trusted registered
May 03 23:51:19 mm kernel: Key type encrypted registered
May 03 23:51:19 mm kernel: AppArmor: AppArmor sha1 policy hashing enabled
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert 'Lenovo UEFI CA 2014: 4b91a68732eaefdd2c8ffffc6b027ec3449e9c8f'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Problem loading X.509 certificate -65
May 03 23:51:19 mm kernel: fbcon: Taking over console
May 03 23:51:19 mm kernel: integrity: Error adding keys to platform keyring UEFI:db
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: Console: switching to colour frame buffer device 240x67
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert ': 8129c1e0865297b1435ad4a47e4f424e'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert 'Microsoft Corporation UEFI CA 2011: 13adbf4309bd82709c8cd54f316ed522988a1bd4'
May 03 23:51:19 mm kernel: integrity: Loading X.509 certificate: UEFI:db
May 03 23:51:19 mm kernel: integrity: Loaded X.509 cert 'Microsoft Windows Production PCA 2011: a92902398e16c49778cd90f99e4f9ae17c55af53'
May 03 23:51:19 mm kernel: Loading compiled-in module X.509 certificates
May 03 23:51:19 mm kernel: Loaded X.509 cert 'Build time autogenerated kernel key: 1fc0e865c21818e2f5cce3868a567b58070b6c0d'
May 03 23:51:19 mm kernel: ima: Allocated hash algorithm: sha1
May 03 23:51:19 mm kernel: ima: No architecture policies found
May 03 23:51:19 mm kernel: evm: Initialising EVM extended attributes:
May 03 23:51:19 mm kernel: evm: security.selinux
May 03 23:51:19 mm kernel: evm: security.SMACK64
May 03 23:51:19 mm kernel: evm: security.SMACK64EXEC
May 03 23:51:19 mm kernel: evm: security.SMACK64TRANSMUTE
May 03 23:51:19 mm kernel: evm: security.SMACK64MMAP
May 03 23:51:19 mm kernel: evm: security.apparmor
May 03 23:51:19 mm kernel: evm: security.ima
May 03 23:51:19 mm kernel: evm: security.capability
May 03 23:51:19 mm kernel: evm: HMAC attrs: 0x1
May 03 23:51:19 mm kernel: PM:   Magic number: 7:946:865
May 03 23:51:19 mm kernel:  memory_tiering: hash matches
May 03 23:51:19 mm kernel: RAS: Correctable Errors collector initialized.
May 03 23:51:19 mm kernel: Unstable clock detected, switching default tracing clock to "global"
                           If you want to keep using the local clock, then add:
                             "trace_clock=local"
lines 730-756