SD Card problem when used an internal storage

[AC Question]

I have Motorola Moto Z Droid (Android 7.1.1) using my SD card as an internal storage but most of time it seems my SD card is not working. Files on SD Card are accessible and files are viewable. but I cannot download anything, I cannot take a picture nor can download anything on whatsapp. When I eject SD card and Mount. It starts working properly for few hours only. Any proper solution??

 

[Rukbat]

It could be a bad SD card, it could be a bad SD card port or it could be a corrupt ROM. There's no way to tell remotely. You have to solve it by substitution. (After running for a while, things warm up, and that could be causing a "just barely working SD card" or "just barely working SD port" to fail.