SOLVED (see accepted answer)
So this one is weird.
Everything was working fine untill I rebooted my phone earlier today.
For some reason, since this reboot, apps are unable to access my SD card storage. As far as I know, no update was applied with this reboot. I do not recall tinkering or changing anything related to this recently.
- SD card is still visible in the storage tab of the settings (there is no available option to unmount or eject it) or in select cases when choosing a folder from an app, however the content does not show up past the root.
- My music player (Oto music) sends an error message "Cannot play this file" while trying to play a song from the SD card
- File explorer will not show the SD card directory at all
- Resillio Sync has a synced folder on the SD card. It now says "Can't open the destination folder". If I try adding a new synced folder on the SD card and select the root of the SD card, I get the message "Android OS restricts access to this folder"
- Google file is stuck in a loop trying to get permissions to access the card
- SD card works just fine on another phone.
- Other SD cards have the same problem with my phone, not just this one
- SD card does not show up when using file transfer with a Windows PC
- Rebooting the phone did nothing
- Removing the card and putting it back in again did nothing
- Formatting the card did nothing
- I factory reset the phone. It worked, but the problem came back at the first reboot.
Current state of investigations I have reset the phone a second time and reboot it every time I install an app, uninstall or disable a system app or change some settings. So far the SD card is still accessible so I know what it's not:
- it's not the fault of disabling system apps
- it's not related to using a work profile (Insular)
- still haven't found an app that causes it
I have no idea what could cause this, all I know is it's related to my phone in particular and it appeared out of nowhere.
I am using Android 13 on ColorOS.
Thanks to anyone who can help.