So it looks like there is still a mechanical friction somewhere and with the model inverted gravity isn’t pushing the components in the direction where the friction is. Tight trunnions are still the most likely culprit. Won’t harm anything to remove the trunnion block and ease the trunnion bores with 400 wet or dry wrapped round a wooden dowel.

re the nose gear door issue, a fix would be to add a second switch valve triggered by the nose gear fully retracting. You would then pipe the two valves in series so that both mains and nose gear need to be retracted before doors start to close. A pain I know but you aren’t going to get enough delay with restrictors and one valve.