Gallery Labs (Legacy Seekbar) Not Working Correctly

[Blackops6]

Whenever I try to use the Legacy Video Seekbar it just goes back to the beginning of the vid, I've tried everything possible but maybe someone has a suggestion thanks. 

[angelchained]

BEFOR CHANGING SETTINGS IN GALLERY LABS: There's a notice in Gallery Labs at the very top>"Not official, used for internal testing, altering settings can cause unexpected corruption." My setting in Gallery Labs for Video player mode is on default, which works seamlessly, but you may want to contact support through the members app or DM an ambassador for assistance.