This seems to be an issue that is affecting multiple users and not just a couple here and there. Using the Private window, clearing the cache, and disabling some of the adblockers still does not seem to fix the issue. Since it is not a one off issue, it should be a fix on the website build or something that is identified as a firefox issue(which then firefox would need to patch a flaw in their code). Since no one seems to mention it being a flaw in the code for firefox, I can only presume that it is an issue that needs to be addressed on the quickbooks side of things.