Blue Iris

I have three HIK DS-2CD2T cameras on BI5, All works fine, but

1, Pre-trigger record and play time do absolute nothing. I walk into view and recording starts after me being in view for 2-3 seconds already.

2, How do i reverse my BI5 installation to the earlier "stable version". Selecting it does nothing after pressing okay.

Any ideas?

Log a support ticket is the best way to get changes made that you feel aren’t quite right.

Are you recording Continiously?
Pre-Trigger only applies to When Triggered and When Alerted, per the manual.