Hi Zilvinas,
I am afraid that will be quite difficult to prove. You see we tested SERP with the customer before the upgrade and this issue did not arise. I suspect it has now come to light because in the live environment hundreds more transactions are being processed that cannot be replicated in a test setup.
Can any techie please review this article and see if it makes sense?
https://docs.pingidentity.com/bundle/pingdirectory-73/page/ygy1564011416825-1.html
I am wondering if it can be solved by changing some Linux settings
Thanks
Lee