I'm so sorry to hear you're having these issues too. I just got the full kit as well with all 4 lenses. We have a critical film shoot next week so I have been scrambling to try and get mine up and running. I haven't experienced any gimbal motor problems, but I'm definitely getting the same terrible video lag, and intermittent video feed cutoff. I also keep getting a "Lens Not Connected" error with the 16mm lens. It took me 15minutes of constantly restarting the drone to get the 16mm lens to work.
Can you report if your gimbal balances out properly with the included balancing rings? I've posted on another thread (Link:
X7 Gimbal Balance Problems), about the gimbals being terribly unbalanced with the included balancing ring. Dji shipped the X7 with the same balancing ring from the X5S, which appears to be 10g too light for the X7, and so it requires a third party filter to be purchased in order for the unit to balance properly, which is very disappointing to say the least.
Once I was able to properly balance my lens, and then restart the unit, I stopped getting the video lag and errors. I wonder if the gimbal imbalance is causing motor stress and failure, which would explain the issues you are having. Please also comment on my DJI forum post to report your experience so that the DJI Staff can see the issues we're having: Link:
X7 Gimbal Balance Problems. I have brought up the issue with them and their responses so far has been hilariously disappointing. They told me "Don't Worry, the X7 Motor can handle the imbalance" and "Read the manual to see how to balance the gimbal"