Vevor is not known for their longevity or high quality. Cheap Asian made equipment is often an entry into getting better made/reliable equipment.
It likely is going to be more costly to try to repair it (and have confidence it would be safe) than to invest in a name brand item with a warranty and better made components.
Yes, the temperature settings can be adjusted precisely. The product description states that it has a 30-410°F / 0-210°C temperature range with high precision sensors that are 50% more sensitive than conventional ones.
