I have avast antivirus. When I got a note that my avast doesn't work with the new version of firefox. When I check Avast it says I am protected. I'm confused.

I recently updated my version of firefox and I got a message that my avast antivirus software was not supported by the new version of firefox. when I checked my avast it indicated that I was still protected. However, I've noticed that the avast is not downloading new antivirus signatures like it used to. Is my avast working?