Normal
Ask anybody that has considerable experience keeping tarantulas, they will all warn you that even a short fall can seriously injure the animal. Either by personal experience or knowing someone that it happened to. If they fall on something like a water dish or anything hard or with an edge to it, etc., that significantly increases the odds of a rupture which is almost always a death sentence. Terrestrial species are simply not designed to take falls from more than a couple of inches. There is no point in risking the chance either. They would not typically climb much at all in the wild, which is why they are terrestrial species. But in captivity we give them a semi/transparent barrier and they will try to navigate it, and are capable of doing so, sometimes at the risk of being injured. They don't know any better so it's our responsibility as keepers to minimize the risk.