WebGL and videoplayer set frame not working in Unity 2019.4.0f1

Hi all!
I have a real issue with WebGL build, videoplayer and UI controls. My application has a part where the user can control a video using a slider component. Basically I’m setting frames of the videoplayer with a slider.

The video works, np. The controls script is simple, and I set slider minvalue to 0 and maxvalue to framecount of the videoplayer component. I tried debugging this in the developer console in Chrome, there is no problem either.
When I release the slider, I get the slider value and set it to the videoplayer.frame. It all works as it should in the editor 100%. However, when I stop dragging the slider in “Build and run” inside Chrome it just resets my video to frame 0 and restarts the whole videoclip.
Does anyone have a clue about how I could maybe work around this issue? I already tried the simple way, also tried giving the videoplayer a few (as much as 20) seconds to prepare, tried pausing video first…Nothing seems to work… I really have to make this work. Or else! Or else what? Exactly.
Thanks for your attention and your time

Luckily the client targeted firefox for this project so it was not a big issue, the same functionality worked out of the box with firefox. I know this is not a solution, so if anyone finds a real solution it would be awesome to hear it.