Hi Juri, looks this problem is duplicate with bz1713556. Can you help to check if duplicate, we can close one.
There is another issue related to kernel/locking/rtmutex.c on 4.18.0-214.rt7.26.el8.x86_64+debug, can you take a look?
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Moderate: kernel-rt security and bug fix update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.