LG G3 some photos are not saved (missing photos)

I've noticed that some photos that I clearly remember taking are not saved. It's something that occurs at ~1% of times (subjective figure). Has anyone noticed this behavior?
Phone & setting specs:

• LG G3 (LG-D855), 32 Gb internal memory, Android 5.0 (Kernel 3.4.0)


• Photos are saved to internal memory


• Internal memory is crypted using LG Security settings (Encrypt Phone)


• I use mostly apps that are secure

It's very difficult to document this problem. It happens from time to time (it's not very frequent), but sometimes I lose important pics.