Set Number of Seconds Before Rules Run in Background Not working

Summary:
Set Number of Seconds Before Rules Run in Background Not working

Content (please ensure you mask any confidential information):

In application→Settings we have made the below setting

Set Number of Seconds Before Rules Run in Background as 30 sec.

expectation is that after 30sec any rule should go into the background, however it doesn't happen and the screen remains in freeze state until the rule is completed. we are using webforms 2.0

we have seen this working with forms 1.0

Has anybody witnessed same issue with forms 2.0? Is it a bug or are we doing something incorrectly? any pointers would be helpful. Thanks!!