DIA0 Critical Database Process As Root

Dear Friends:

In alert of my instance the following message appeared:

DIA0 Critical Database Process As Root: Hang ID 21 blocks 4 sessions
     Final blocker is session ID 372 serial# 50443 OSPID 20510 on Instance 1
     If resolvable, instance eviction will be attempted by Hang Manager.
 I have noticed that an import takes longer than normal.



I am using oracle 19c (19.15.0.0) on oracle linux 7.9

Oracle recommended the following action, which I did:

alter system set "_enable_shared_pool_durations"=FALSE sid='*' scope=spfile;

But the same error followed.

What I can do?

Thank you