Superb estate mk 2 electricl tailgate repair didn't work!

I have seen multiple posts about electric tailgate faults but none are precisely the same as mine. New car to me, tailgate initially fine, then intermittently working then not at all. Auto electrician not sure, no relevent error codes. But one ram not working so replaced. Tailgate now opens a little on every press of the button, any of the three. We're stumped why it now has a different fault. Any advice would be very welcome, also whether I can easily convert to gas struts, as reluctant to keep throwing money at such an unnecessary feature!