I never suggested that you downgrade the server. Instead you should update the SN to proceed.  
Hello, after upgrade NetWorker from version 19.1.1 to version 19.7.0 I've noticed next problem:backup over storage node (different as NetWorker server) on version 19.7.0 does not work anymore (hang and/or fail)!It doesn't matter if this storage node works with Tape Library or Data Domain.Backup over NetWorker server works (but server is virtual machine and can not be storage node for Tape Library!) When I downgrade on specific storage node on previous version (19.1.1) it works again!I've upgrade now on last version 19.7.0.1, but the problem stay! NetWorker server runs on RHEL 7.9 OS. Does anybody have same experience and what can be wrong?   Regards, Andrej  
Problem with storage node on NetWorker version 19.7