Exception error when logging into FreePBX with FireFox

Exception err: Can’t convert custom provisioning address ‘’ into a valid URL. This must be in the format of protocol://host:port - Please re-enter
/var/www/html/admin/modules/endpoint/functions.inc/functions_common.php

I can log into FreePBX using the same URL from the same PC using Chrome or Edge.
Other PCs on same network can log into FreePBX using FireFox