I got used f310, updated to 320bt (by soft), every time I find a radio station and I make it remember (by holding station no on display) then I detach the panel or simply leave the car (with panel attached) start again and the stations are missing. I have to find them again etc. Before updating there was the same situation so I thought the update will solve it.

Do any of your settings save? Or only radio presets

Sounds like the CMOS battery is defective or your EEProm the settings are stored in is malfunctioning.

All the setting seems fine. When I do the pull up for a short time it's ok, when for longer ~hour time it's gone. The battery from the front panel is ok (at least when I check it's full or almost full, the panel is set to 'off' position). Or maybe it's not the front panel case or just a time of leaving the radio turned off (without ignition), how to check CMOS battery or second thing?

OK, solved. As I have VW I had to swap red and yellow cables between ISO and Avic.