It’s been going on since Android 6 . It was happening in FP2 days etc.
Fairphone. I’m not sure there is a fix but a warning may be useful that’s if people read all the instructions manual etc, which of course do not come with the phone.
As far as recovering more info may be usefull.
Did you have photos on the phone before inserting the SD card?
Did the camera continue to save or stop?
Have you removed the SD card and done anything to it i.e. try to reformat it etc.
Is the card back in the phone.
OK Have you tried using adb to access the phones memory to see what you can find?
Although I use a Raspberry Pi here is some idea of how adb can be installed and used.