Vlad it's definitely happening in Orion, and it's been happening for a long time on Safari I think. At least I tried various video speeder extensions for at least 2-3 years on Safari, and they all suffered (and continue to suffer, up to the latest Safari version) from the exact same problem as Orion does.
I'm not an Orion supporter (yet) so I don't feel entitled to a solution... but for me it's a deal breaker. What interested me most in Orion is that I could use the same browser on MacOS and iOS, and on iOS even my favourite extensions were supported. But I spend enough time watching video on speedup (and speeding up and down constantly), and saving so much time doing so, that it's a huge, huge functionality for me that has to work flawlessly if I'm ever to give up Chrome.
If you can't replicate the problem, I'm happy to demonstrate it to you over screen sharing. It happened to me consistently on various Macs over last years, Intel and M-series.