If you have two out of two, either you're the unluckiest person alive or you're doing something wrong. Based upon my own experience, I put sandpit voids in the bowl at approximately 1 in 150. And they've always showe up in the first few bowls in my experience. I had one about 1/2 way up on a rather thin bowled pipe that burnt all the way through. The second was in the area yours is and it showed up after the second bowl. Your photos look like a pipe that's been smoked for awhile.
Not trying to pick on you but I can't help but wonder if you haven't tried smoking to the bottom of the bowl too much and caused that burnout by lighting too much.
Each of those 2 pipes were smoked 3 times (I received them this Tuesday)
It had a "carbon" layer already from the factory, that's why it maybe looks smoked for a while.
It COULD be it was my fault, but I doubt it. I treated them exactly as I treat all my other pipes and this is the first time ever this happened to me (and 2nd time unfortunately)
The second one (I haven't posted photos of that one) has a much more shallow "crater", so I already mixed up some pipe mud and applied to the wall. I'll apply another thin layer tomorrow and then day after that. I won't even try to return that one because it's not as critical IMHO.
I'll most definitely try to return the one from my original post in this thread and see how it goes.
Maybe pipe gods are trying to tell me to stop buying Autographs