I have a Liebherr freezer/wine fridge (SWTNES 3010-25A). After about a year of owning it, the freezer started to "defrost" itself. I would open it up, and it was wet inside. Checking the temperature with a hand held thermometer it would be above freezing, but the door panel would say -25C. After I turned it off and back on, it would refresh the temp and start to freeze again. Started off slow, but now this is a daily occurance. I've been fighting with the service company over the past year. They replaced the inverter, the white temp probe that is visible on the inside back panel, and the controller board. They won't do anymore nor do any replacement. So far I replaced the fan and fan motor inside (the one that is behind the inside back panel that seems to blow the air from the condenser around the freezer). I'm unsure of what else to replace as most of the parts have been swapped out already. I'm thinking it could be the limiter or the defrosting heating thing, but I'm not sure.
Here is a video showing the issue https://youtu.be/vzMh5Mr6HC0
What I did notice is I can tell when it's not working as I don't hear the ice being made. The ice tray seems to know that it is above a certain temp, but the freezer doesn't (if that makes any sense).