It may be 4 things (and maybe more than 1 at once):
1 - Fake or generic microSD
2 - Bad or defective card reader that you've used on PC (personally suffered with bad readers for more than 10 years until last year I bought quality readers on amazon, it even "revived" some cards that I've considered condemned. In Brazil we have almost zero access to buying quality readers)
3 - Defective microSD, if it's original, try exchanging using warranty.
4 - Computer's OS corrupted the filesystem on its own.
1 - Fake or generic microSD
2 - Bad or defective card reader that you've used on PC (personally suffered with bad readers for more than 10 years until last year I bought quality readers on amazon, it even "revived" some cards that I've considered condemned. In Brazil we have almost zero access to buying quality readers)
3 - Defective microSD, if it's original, try exchanging using warranty.
4 - Computer's OS corrupted the filesystem on its own.
















