As it is not possible to remove these users, even when using cloudadmin, we will want to resync the Identity Source to try and release these stale JIT users. Please do this by editing the current Identity Source, typing in the password for the user, and clicking "Save". Once that is done, confirm if the stale JIT users have been released from the Users and Groups section.
If the users are still visible after attempting the step above, please file a Support Request with VMC Global Support (Creating and managing Broadcom support cases) to manually remove the stale JIT users.
Please provide the below information when filing the Support Request: