It seems to be the latest Windows update (May 2020 Update)
I was able to check and uncheck the option, but after the May update if I check it, it remains checked and I cannot uncheck it.
However if you click the "Get OneDrive Insider preview updates before release" option under About Tab, seems to solve the problem.
Looks like they found out about it and they will fix it in the next update, so can you have it fixed with the insider update.
Worth mentioning that the insider update can have other problems that they are still testing.