In my case, what led me to make this change is that I took an old link saved in favorites that was supposed to show me a thread. In Brave I couldn't read it, I always received an error message. In Firefox the same link opened on the first attempt.

However, I can still find some problems.
This image is of logged in FF (error), and anonymous FF (thread displayed normally).

After I load the thread in private mode, if I refresh the page in logged in mode and I can view it. Bizarre... but it works.