Can't delete folder in VAULT

I can’t delete a folder in MacOS. All contents incl. subfolders can be moved, renamed and copied, but one subfolder cannot be deleted. This subfolder too can be renamed or moved into another folder in that same VAULT… but can’t be deleted.

In below pictures, Folder01 is the parent folder. In that parent folder, there is said subfolder which cannot be deleted.

Set-Up:
MacOS 15.4.1
MacBook Pro Apple M1
Cryptomator 1.15.2
Fuse-T 1.0.47

This is the Folder01 I try to delete:

The persmissions are OK to delete this folder:

But upon confirming to delete, this error pops up:

When trying to delte the SUBFOLDER, this warning pops up:

Exactly the same with Windows 11
I don’t know what to do !