I'm not on my PC to double check right now but maybe turn hardware acceleration off (or on, not sure what default is) I remember having issues years and years ago and I believe it was hardware acceleration. Worth a shot at least.
Can't say I've experienced the same issue as you though.
Alternatively could always try Librewolf
I just use both. Lemmy for general browsing and Reddit when I want a more specific community that isn't around yet.
I was never a 3rd party app user really as I just use old.reddit through the browser on my phone so until old.reddit is killed off I'll probably continue to use both. Once thats gone though I won't be using Reddit, new UI is truly awful
Think my DNS is blocking them too, keep seeing comments about ads and I haven't seen a single one lmao