Since MacOS 11.0’s dev beta was literally just released a couple days ago, there’s probably TONS of issues. Obviously Roblox will need to patch this issue but what I’m saying is that it could take a little while for a patch to come out, for two reasons:
Barely any of their player base is using the dev beta; even when the public beta comes out it will still be a small percentage
There’s a lot of new features with the update, and with them needing to support all of the stuff coming out it will take a while for that to happen
Appreciate the enthusiasm on jumping to the latest and greatest, but joining a beta for a new operating system is completely at your own risk. We find out along with every other company at WWDC. We have not begun supporting Big Sur (it’s less than a week old). We just started planning for our QA team to do passes on the beta.
At this time, I have no ETA for when this will be resolved. If you wish to use Roblox Studio as its intended, the latest supported version is Catalina.