Script task, Expression Editor - can't confirm Save & Close button, v 20.4

Hello,

after Appian upgrade to version 20.4, I have a problem with confirming Save & Close button in Expression Editor



Close and Save & Close buttons are now up and when I try to click on Save & Close button it's like I'm trying to edit that button.
I can't confirm it. Any suggestions? How to solve that problem?

Thanks, 

BR