The other half of your problem is the tasting like nothing. Long cooking in liquid leaches flavour out of the meat and into the sauce, which is fine when the sauce is the point, and less fine when you want to taste chicken.
Browning the thighs hard in a pan first makes a big difference, and so does salting them 30 minutes ahead. A dry surface and real colour before they go in gives you something that survives four hours in liquid.
Seconding the vent. Also check the lint trap housing itself with a torch, not just the screen. A layer of felt builds up in the duct below the screen and it strangles the airflow while the screen looks clean.
You carried it in on your feet.
Wet shoes on carpeted mats put a surprising amount of water into a sealed cabin. Overnight it evaporates, and in the morning the glass is the coldest surface in the car so that is where it condenses. The rain outside is irrelevant except that it wet your shoes and the pavement.
Things that help, cheapest first:
If it fogs even after dry days, then you have a leak and that is a different conversation.
Second thing to check: your cooker. There is a lot of variation between machines and newer ones from some brands run noticeably hotter than older ones, while some run cool enough that low never really gets to a proper simmer.
Cheap test. Fill it two thirds with water, put it on low with the lid on for four hours, and stick a thermometer in. You want to see something in the 90s Celsius. If yours is sitting at 80, that explains everything and you should be using high for braises or adding hours.
The fork twist is the only test worth teaching a beginner. I stopped using a thermometer on braises entirely. Once you have felt the difference twice you never go back.
The loaf tin point is worth expanding. A tin inside an oval opens up things like meatloaf, bread pudding and cheesecake, which are the recipes people think slow cookers cannot do.
The etching test is the important half of this. Once glass is etched by years of hot dishwasher cycles in soft water it looks similar and no amount of vinegar brings it back, and people spend money chasing it.
Second cause, and it is the one nobody wants to hear: old beans never soften. Dried beans do not last forever, and beans that have sat in a warehouse or a cupboard for two or three years can be cooked all day and stay chalky.
There is no way to tell by looking. If you have followed the tomato advice and they still refuse after seven or eight hours, buy a fresh bag from somewhere with turnover and try again. It is not you.
Two weeks is slow but not abnormal, and the fuzz is your actual problem.
You have a supersaturated solution that would rather grow crystals anywhere than on your stick. Every dust speck, scratch and rough edge is a nucleation site competing with the skewer, and the crust across the top is thousands of tiny crystals winning that competition. Once the crust forms it also seals the surface and slows evaporation, which is why growth stalls.
For the next batch: use a more concentrated syrup, closer to 3.5 or 4 parts sugar to 1 part water by volume, fully dissolved at a low boil. Let it cool to lukewarm before lowering the stick in. Cover the jar with a paper towel and a rubber band instead of leaving it open. Use a clean smooth jar. Seed the stick by rolling a damp skewer in dry sugar and letting it dry hard for a few hours first, so it is the most attractive surface in the jar.
With that you should see obvious growth in three or four days and a decent stick in seven to ten.