Hi, Gallen. As the owner of (I'm embarrassed to say it) three Class B fridges inside four years, I feel your pain. We had trouble with both of our Dometic 2351 propane models, to the point where we couldn't use them on the road. We eventually got a Vitrifrigo, which is a marine-grade compressor fridge, and have been very happy with it so far, even in the Texas heat. If you are interested, you can read about our sorry three-fridge adventure in a blog post
here.
We were able to rehab both of our Dometics simply by burping them, believe it or not. There's plenty of flap-trap on the internet about how burping is an urban myth or whatever, but it worked for us. We just turned those suckers upside down for a few minutes, flipped them back upright, and voila - they started cooling again.
That's rather impractical for a propane fridge installed in a van, however. But it's a zero cost first intervention measure. If you de-install your fridge and burp it and it does NOT restore functionality, then you know you've got bigger problems and you can move on to other testing.
As an anecdote, rather than sell our Lazarus fridges (as I call them) on Craigslist, we decided to combine them to make an off-grid fridge for our garage. This was my husband's idea - he is a "DIY or die" kind of person (so am I actually). We live in hurricane country (Galveston County TX), so this could be very useful to us in the event of a significant power failure. We also had a Lifeline AGM battery and an electrical converter left over from our van's lithium conversion, plus a spare propane tank, so we had most of the pieces already in surplus (all except the wood and plumbing). We are in the progress of putting it all together in a contraption that looks like this. The propane bottle will be mounted on top, and I will stain and seal the wood enclosure so that it has a finished look. Nobody in their right mind would set out to make a thing like this from scratch, but we had the parts, so....