Hello and welcome to the forum
I'm unable to give you any technical answer but I'm sure some of the forum members will have experienced similar situations over their many years of owning caravans.
However your problem sounds to me like one of those situations where you may need professional help and advice. I'm sure you will have a mobile caravan engineer within a reasonable distance of your location and in the absence of any more detailed advice from forum members I would recommend you get the engineer to visit to give you a full picture of what the situation is.
Some of the members of the forum can post links where you can enter your post code and find approved engineers close to your area. Very often you get reviews regarding people's experience of dealing with the engineers.
I believe that because they are usually individuals working for themselves, then if they weren't dependable they probably won't stay in business very long. Plus to get accreditation they have to commit to receiving training at their own expense.
So they tend to be familiar with the equipment fitted to most caravans. And committed to giving a good and friendly service.
Best regards Brian