Moved to the Android subforum.
In the past, Dolphin always saved to a folder named dolphin-emu. Could you go to Settings > User Data and check where Dolphin is saving right now? If it's not the dolphin-emu folder, please move the contents of the dolphin-emu folder into the new folder.
The reason why Dolphin has started using a new folder now is Scoped Storage. You're supposed to be able to keep using the old folder until you uninstall Dolphin, but unfortunately there's a bug in Android 11 that makes this stop working if you reboot your device.
In the past, Dolphin always saved to a folder named dolphin-emu. Could you go to Settings > User Data and check where Dolphin is saving right now? If it's not the dolphin-emu folder, please move the contents of the dolphin-emu folder into the new folder.
The reason why Dolphin has started using a new folder now is Scoped Storage. You're supposed to be able to keep using the old folder until you uninstall Dolphin, but unfortunately there's a bug in Android 11 that makes this stop working if you reboot your device.