Thank you for your bug report, the error seems to be 

2024-04-27 08:22:15,842 DEBUG subiquity.server.controllers.filesystem:1182 GuidedChoiceV2(target=GuidedStorageTargetReformat(disk_id='disk-nvme0n1', allowed=[<GuidedCapability.DIRECT: 2>, <GuidedCapability.LVM: 3>, <GuidedCapability.LVM_LUKS: 4>, <GuidedCapability.ZFS: 5>, <GuidedCapability.ZFS_LUKS_KEYSTORE: 6>], disallowed=[GuidedDisallowedCapability(capability=<GuidedCapability.CORE_BOOT_ENCRYPTED: 7>, reason=<GuidedDisallowedCapabilityReason.CORE_BOOT_ENCRYPTION_UNAVAILABLE: 2>, message='not encrypting device storage as checking TPM gave: cannot connect to TPM device: no TPM2 device is available'), GuidedDisallowedCapability(capability=<GuidedCapability.CORE_BOOT_UNENCRYPTED: 8>, reason=<GuidedDisallowedCapabilityReason.THIRD_PARTY_DRIVERS: 4>, message='Enhanced secure boot options cannot currently install third party drivers.')]), capability=<GuidedCapability.LVM_LUKS: 4>, recovery_key=None, sizing_policy=<SizingPolicy.ALL: 2>, reset_partition=False, reset_partition_size=None)
2024-04-27 08:22:15,843 DEBUG root:38 finish: subiquity/Filesystem/v2_guided_POST: SUCCESS: 500 Traceback (most recent call last):
  File "/snap/ubuntu-desktop-bootstrap/171...
2024-04-27 08:22:15,843 DEBUG subiquity.server.server:541 request to /storage/v2/guided crashed
Traceback (most recent call last):
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/common/api/server.py", line 164, in handler
    result = await implementation(**args)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/server/controllers/filesystem.py", line 1184, in v2_guided_POST
    await self.guided(data)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/server/controllers/filesystem.py", line 726, in guided
    gap = self.start_guided(choice.target, disk)
  File "/snap/ubuntu-desktop-bootstrap/171/usr/lib/python3.10/functools.py", line 926, in _method
    return method.__get__(obj, cls)(*args, **kwargs)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/server/controllers/filesystem.py", line 645, in start_guided_reformat
    self.reformat(disk, wipe="superblock-recursive")
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/common/filesystem/manipulator.py", line 257, in reformat
    self.delete_partition(p, True)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/common/filesystem/manipulator.py", line 120, in delete_partition
    self.model.remove_partition(part)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/models/filesystem.py", line 2110, in remove_partition
    for p2 in movable_trailing_partitions_and_gap_size(part)[0]:
  File "/snap/ubuntu-desktop-bootstrap/171/usr/lib/python3.10/functools.py", line 889, in wrapper
    return dispatch(args[0].__class__)(*args, **kw)
  File "/snap/ubuntu-desktop-bootstrap/171/bin/subiquity/subiquity/common/filesystem/gaps.py", line 281, in _movable_trailing_partitions_and_gap_size_partition
    part_idx = pgs.index(partition)
ValueError: Partition(device=disk-nvme0n1, size=536870912, wipe='superblock', flag='boot', number=1, preserve=True, offset=1048576, partition_type='c12a7328-f81f-11d2-ba4b-00a0c93ec93b', path='/dev/nvme0n1p1', uuid='b6e20e0a-4c0e-4c87-9d12-8229abbf2190', id='partition-nvme0n1p1', type='partition') is not in list