Mozilla has been migrating Firefox extensions to a new software architecture. This has caused problems for existing extensions, including F123 Access. We have waited for Firefox to stabilize and complete the needed internal change, before we decided how to make the move to the new architecture. We must move or else F123 Access will not be allowed to run on FireFox.
We are about to start work on a new version for Firefox, and we have a design which should make us able to migrate to other browsers such as Edge and Safari.
But current compatabilty problems with our existing version on the changing Firefox are severe enough for us to ask our users to transfer their use of F123 Access to Chrome, until such time that we can build, test and release a new version of F123 Access on Firefox.