I never claimed to know anything about game coding, which is obviously what Roblox is about, but I do know browsers can be hijacked like you seem to be implying the game was. I mean I HAVE done extensive modding on some games, but mainly just adjusting CVAR values by following guides.
The forum I linked to is dated Sept 18, late last year. I have no idea if that was before or after the author stopped supporting the game, but since most of it is about dealing with exploits, it seemed pertinent.
Again, I suggest you read it and better yet, jump into the conversation. It's specifically FOR Roblox developers. Many there have posted suggestions they claim have helped, but again, I don't really know if it's still useful, as it may have been bandaid solutions added to the author's attempts at security.
The bottom line here is regardless whether one is code savvy, this is a security issue. What you have to solve first is getting your browsers back up and malware free. Anything capable of "breaking" Chrome has got to be pretty significant, so you need to consider antirootkit and anti trojan tools if a mere reinstall and reset doesn't fix the browsers.
It's also common sense that if it really is a situation now where the game is controlled by hackers, to avoid it like the plague. That very well may be why that forum thread ends at Sept 18.
One thing I do if a game I DL can't be accessed via a secure distribution site like Steam, GOG, Uplay, etc, is to use Epic Privacy Browser to access it. I also always have a VPN running. Epic is built on Chrome, but it doesn't have Google tied to it and the address bar entries are not traceable. They even use their own servers for searches.
Knowing code means nothing if you jump on public servers and get reckless. What you should be learning is how to safely use your PC on the internet. No advanced expertise can replace common sense. What damage you caused by neglect may end up requiring System Restore or even a complete reinstall of Windows.