@curlycord
Firefox will allow you to enable deprecated forms on TLS.
Open a window, navigate to "About:config", search TLS, switch "security.tls.version.enable-deprecated" to a value of True. Had to enable this in order to access the GUI on Panasonic NS700's.
That being said, UCx is an actively updated platform, as opposed to the recently-defunct Panasonic, so it should have up to date security protocols.