Here is the trick. Go into Camera Settings then into Photo/Video and under Video settings there is a thing called Dewarp. You have to turn this ON. That should fix your problem with barrel distorted images ?
Let us know, I am pretty sure though that this is the culprit. With DJI products, especially when you update FW some of the settings change to what some "smart" software engineer thought would be a sensible default. Unfortunatelly more often than not those defaults do not make much practical sense. Worth always checking all your camera settings not only after FW update but pretty much before every flight to avoid nasty surprises when you come home to only find out that the resolution of your video has changed from 4K to 1080 or your frame rate changed or with stills your ratio is 16:9 instead of 4:3 etc etc...
