What I did was type:
Do you have Conversation Button under Avatar installed?
^^ the bold is a result of the copy/paste...
and then I highlighted the whole sentence and clicked the Remove formatting button, but it didn't do anything.
A little further digging and I figured out that if the bold text is on the same line and bounded by the non-formatted text, it will remove the formatting. But if the bolded/sized text is on the next line, it won't remove it.
Do you have
Conversation Button under Avatar installed?
^^ this is what happens when I hit ctrl+v right after "have", and this formatting won't get removed.
Another oddity is that it seems to work properly in the advanced editor like the one used to create a thread, but not in the quick-reply.
Even stranger, if I enter the text into the quick-reply, then click "more options" to go to the advanced editor, then I click the back button, I can remove the formatting. So maybe the auto-save changes something
I don't know if this is a bug or not but I figured I would mention it.