Would love some Help diagnosing a VoiceOver Bug that Appears to be API related

So for a while now, I've been having an issue with the Twitch mobile app where whenever you watch a saved video, the percentage slider will allow VoiceOver to swipe up and down to change it, but the slider's value immediately moves back to the position it originally started at, meaning that it is now inaccessible for Voiceover users.
I would've chalked this up to a Twitch issue, but the same issue appears when using the Nintendo Music application (which for testing purposes does require a subscription to Nintendo Switch Online, and it isn't the most accessible piece of software). But given that this is a consistent issue on two completely separate apps, I'd love people's insight into what specifically could be breaking this. Is it because VoiceOver now doesn't treat sliders without labels properly?