Is there a reason why my videos are constantly stopping every 4-5minutes of recording? Or is it a setting I have missed somewhere? I have the video cache set to 16GB, should this be on auto?, I am using a Sandisk 64GB Extreme Plus micro SD card. This was happening on my 16GB and just thought it was the card getting full.  It happens regardless if i press the record button on RC, or my iPad mini4.  Most of the time I am recording in 4K 30FPS (3840x2160), but I have started recording in 2.7K 30FPS.

It should not. You see the SD  storage on the app which tells you how many pictures you can still take or how minutes left for video.

Do you have the same issue when you are using the original SD card of the drone? Please try to format the SD card via DJI GO 4 APP, see if it is better.

Yes same problem on the original, thats why I bought a new one, I thought the original card was bad.  Both of them have been formatted while in the mavic