After my 4 yo (not cheap) Waeco fridge/freezer stopped working, the compressor ran non-stop, I did some googling & found it's a common problem. So I replaced it's thermister, which is a fancy term for the sender, this didn't work properly either although it was a small improvement - problem being it was still sending the incorrect temperature!!
While I was replacing the Waeco sender I stuck another one in with it which is connected to my Pi4 so I can monitor what is going on. This is how I found it wasn't cycling properly.
So, I bypassed the waeco circuitry & installed a separate controller, with it's own sender (same as I'm using for my fridge & hot water) - works great.
I can switch between the new controller & the original Waeco if need be - it might come good one day!!
You can see the difference in temperatures - Waeco showing +18 when it is actually -3.3C