Ensure you have video switch set, and card (min. 40 MB/s write speed) has enough space.
Dual ISO does not work for video.
RAW video crashes the camera (need to pull battery out, wait 30s) if you use raw_twk.mo.
RAW video (14 bit) varies how it stops based on resoution and and fps.
After you hit stop stop record or it stops because of skipped frame, you have to wait for the camera to finish its processing, else you get weird behaviour.
To get most from RAW video (14 bit) continuous, ensure you dont exceed 720p /24fps. ISO 400 max.
The highest useful 14 bit raw resolution of 1600 @2:35 /24fps, and it will run about 40s or more. ISO 400 max.
If you use higher resolutions you get clip times less than 30s, which tends to limit things.
5X mode supports 1080p and even 2k but you lose AF tracking, it forces 30fps, and the clips are less than 5s.
The best video low light mode is H264, flat profile pic shot flat, ALL-I at 1080p 30fps, ISO 1600 max.