Sequoia 15.3.1 Safari issues

Since the update to Sequoia 15.3.1 I have massive issues with Safari. Nearly all websites don't open, sometimes one can see that the page gets reloaded several times without opening. This esp happens when Citrix Receiver is running or has been running in the same session before.

If I want to use Safari I need to restart the MacBook. Closing Citrix does not solve the problem.

This issue is new since the update.

MacBook Air, 2020

1,1 GHz Quad-Core Intel Core i5