currently, it seems that many people, myself included are having issues with watching shows on dub servers, with unexpected quality changes and random server switches practically making watching anything in dub rn impossible.
I have gone to other websites and tried to watch there and had the exact same problem, so I think that this is a problem related to the servers that we get the streaming off of and not a problem of the website itself, Currently, I know no real fix for this other than going to another website that doesn't use the same streaming servers as aniwatch, etc.
TLDR: dub servers are tweaking, probably not the website's problem.