Hello, yesterday I have updated the firmware to the latest version that is available on 3CX. Unfortunatly after that upate I cannot use CTI anymore. More specificly I cannot select any number in the Windows client and start the call on the desk phone. With the prior firmware all was working well. On the web interface of the phone I can danwoload the firmware that was running prior on the phone and the installation works. But as soon as the update is done and the phone is reprovisioned it downloads the latest firmware again. My guess is that the firmware was updated but the 3CX server itself is not jetzt updated to 15.5. AFAIK it is still running on 15.0. I currently cannot update the server software to the latest version. Is there any option in the phones configuration file where I can disable this?