BraxtonBrewery, as mentioned a few posts ago...also check that you've broken the metal tab between the two outlets from Photo 3 in Post 3. (Use pliers to bend the metal back and forth to sever the connection.)
Otherwise, your fridge will be turned on when EITHER cooling OR heating is required. The fridge will turn on when the temp reaches 1c above your target temp. But when the temp reaches 1c below your target (i.e. when it's already cold enough), the heat function will activate but with tab unbroken, the heat relay is also connected to your fridge.
Eventually, your fridge will overheat and won't bother turning on when it needs to - giving you random results. (The ice cube lamp test will leave your lamp ON even when it's BELOW your target temp.)