Hi everyone,
I tested the X7 going back to 2.2.11, and it does not really make a difference because this is a actually a template option set by 3CX rather than the firmware.
This provisioning behavior has not changed at least since 2 years ago, so the fact that it was working for you would imply that you perhaps made some change along the way to make it work that way? (ie. Default Dial Mode = Video)
To make the change you probably did either of the below if I had to guess:
a. built a custom template and replace the Default Dial Mode
b. removed the provisioning link and changed the option in the phone menu so it stays that way