It's a common problem that's somehow related to storage access and how apps handle it, in relation to the OS.
As I learned from a lot of lurking, this affects Gmail, but also Telegram and other messengers, some games, some apps that require direct storage access for caching...
I think it's something that either app creators will have to fix, or the creators of the ROM.
Either way, you're not alone, this drives me insane as well.