Sounds like they will come through eventually. And this house may not be lost, the next people in all likelihood will go through similar shit you are now, so the race lead is still yours.
Because underwriter stage is the last stage before mortgage offer. I remember my MA telling me that they operate at their own pace, can't be chased ( I was trying to chase it up), but they do eventually come through and that should be it in terms of the decision.
Sounds like they will come through eventually. And this house may not be lost, the next people in all likelihood will go through similar shit you are now, so the race lead is still yours.