Freeze on "Loading initial ramdisk" on 21.04 (kernel 5.11)

[MilkBoy]

CPU:
Vendor ID: GenuineIntel
CPU family: 6
Model: 94
Model name: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
Stepping: 3

Microcode:
intel-microcode 3.20201110.0ubuntu1

won't boot at all. Tried proposed updates, but same result; stuck on loading initrd

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package:
ProcVersionSignature: Ubuntu 5.8.0-50.56-generic 5.8.18
Uname: Linux 5.8.0-50-generic x86_64
ApportVersion: 2.20.11-0ubuntu65
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Sat Apr 17 15:40:20 2021
UpgradeStatus: Upgraded to hirsute on 2021-04-17 (0 days ago)

[MilkBoy (michael-wikberg)]

So, after installing/removing kernels several times, now linux-image-5.11.0-16-generic manages to boot up correctly, even though there seems to be a random 5-20 second longer wait before asking for disk encryption password (compared to 20.10 with 5.8 kernels). I so have no idea what's going on here :D

[Kurazs Iosif Daniel (kjdro)]

Hello,
 I can also confirm, starting from 2021-May-10 my Ubuntu 20.04 installations wasn't booting. From what i think might be the root cause, is some security update that went in the day before that might have updated something. All i know the next day no matter what kernel version i was choosing the boot always hanged after initrd command. No matter what i was doing i could not get more logs to be prompted.
At one point i managed to reinstall grub, then proceeded to an apt upgrade, which broke my system again, and now i cant fix it by reinstalling grub.

My setup:
2 ssd's the boot and efi partitions are ext2
then i have 2 other partitions both encrypted, that share a vgroup where my root, home, swap partitions are.

I suspect that the problem comes from insufficient testing with encrypted setups.