I agree with @relaxvideo, prepare the file in Insta360 Studio App first, besides you will catch all the gyro-stabilizing data automatically processed as well so you won't get confused with it, then put the 360 video into VEGAS Pro.
Or, the other alternate around in new version of 5.0.0 that allows the sequencing editing cutting and reframe of what you need, you can do that there and later do finishing in VP21. The weakness in this way is not yet supporting the 25p frame rate. The project only still 30p.