I'm running Cynanogen 13, 20i, I'm rooted, have sd card formatted as portable. Any files I copy there are erased on reboot of phone. Does not matter if copied from storage, pc via usb or via usb otg flash drive. Is there a fix?
Thx,
Shneor
I've seen weird things happen like that on knock off cards, ones that aren't really the capacity they claim, etc. I would look to that first, especially if you got a "really good deal" on it from Amazon or Ebay. If you went to a physical brand name store, it could just be faulty.
This is a Sandisk SD card, works great on any other platform. It has also happened on another SD card, so it has nothing whatsoever to do with the quality of the card, just a MM issue, as this card worked just fine in 5.x. Files stay so long as I don't reboot.