Default G2 F320 microsd problem

Hi. I just got a 64GB microsd, works flawless. The problem is that I can't seem to transfer files from my internal memory to the microsd. But if I connect my phone to the PC by MTP, it can. Even transferring from the PC to the card.

Transfering, creating folder etc on the card doesn't work just by using the phone. The only apps that can use it is the LG Backup. I backup all my files, settings etc just fine to the card.

Any idea why it is like this?