[jcgc]

Just received and set up this 10E yesterday. I moved a Samsung EVO 128gb card from the old phone to the new. The old phone is an LG G4 with OS 6.0. The 10E started with OS 9.0 and updated to 10.0. The problem happens on both of the new OSs.

I have intermittently been unable to write to the SD card. I removed and re-installed the card and it worked temporarily and later when it happened again I found the card was unmounted and mounted it and it worked again. Now in just a few minutes it has stopped working again.

Any ideas on a solution?

[Rukbat]

If it only happened on the G4, I'd say an intermittent SD port. But if the same intermittent problem is happening with the S10, I'd say it's a bad card. Stick it into a PC and copy everything you can before it goes completely. (You didn't "move apps" to it, did you? That can kill a card quickly.)

[jcgc]

It never happened on the LG G4. It has started happening with the 10E. I tried formatting it twice now on the 10E and it failed despite saying it had completed. I know this because nothing was deleted. Again, briefly after that you could write to it and then couldn't. I'm picking up a new card and will see how that works. I'm hoping this isn't an issue with the phone.

[jcgc]

Though I would update this. I installed a new 128gb card and it has worked fine. Glad it was not the phone.