Third time won’t be the charm if it’s a space heater. I did the math on this before at some point; can’t remember it exactly, but what it comes it out to is that an Inkbird can’t handle the average heater. Another guy had his melt exactly the same way.
Looks like someone else was using his on low and that’s an amperage they can handle, at least for his particular heater; I’d be careful though. I think most space heaters pull more than 900W on low, which is what his did. They also pull a bit more amperage when they’re starting up than normal operation.