Go to SETUP (spanner symbol)
- Save Data Setup
- Copyright Information - change the information on Copyright and Author here)
It is well buried I have to admit but this should solve your problem.
Have you considered trying Davinci Resolve? I have used it with 4K H.265 4:2:0 generated with an X-T3. Color grading tools are excellent. Works well on a Mac. But I know there is Windows version. You can download the very powerful freeware version 17 that has no time limits to see if it works for you.
I bought a used xt2 and want to delete the previous owner from the camera. I’ve reset the settings but “all rigts reserved” has the previous owner. Is it something that follows the camera from when it was registered. It’s annoying.