Have a 80D....at least once a day during filming it freezes up and that file that is not recorded...obviously this is a problem. The strange thing is that I sent it back and B&H replaced it...the 2nd one does the same thing. Makes me think it's on my end...any ideas? Would the speed of the SD card have anything to do with it?
Been using the 80D for 2 3 years now (since it release) never came across this problem myself.
But it sounds to me that the SD card is the problem. Maybe not the speed but the entire SD card.
Have you tried to use a different one?
I use the SanDisk SDHC EXTREME PRO UHS-I U3 95MB/S and never had any problems