taking the risk of asking the most stupid question: have you chosen "disable" in the IQ menu, page 3/3 auto update custom settings?
If it's set to disable and you switch off your camera, all your changes of settings will not be saved.
What I usually do: set this point to enable, change the settings, switch the camera off, switch the camera back on. Then change it to disable.
Now all your settings are safely stored!
🙈