Video slider sliding halfway past video

I have a simple slider set up with two videos in it and the slider seems to be scrolling past the second video and landing halfway through it.

The bug only happens occasionally, I can’t always recreate it, and when I go to inspect it, it pops back into place.

Has anyone encountered anything similar?

Also it’s throwing multiple errors that say:
Failed to execute ‘postMessage’ on ‘DOMWindow’: The target origin provided (‘’) does not match the recipient window’s origin (‘’).

I’m not sure if the issues are related.