it's not the straight tube, not the down tube, but the tube that runs crosswisethe prang is 5mm long, 2mm dent.
It is possible that birds got into the insulation and fluttering around moved or packed down the insulation.Is this area near vents,electrical service coming into the house? If so that can act as a heat sink for heat loss.Good luck.D
What is the girth of the cross tube? Going on the measurements you supplied, the structural integrity of the bike is most probably fine and safe to rideHowever to be safe you should get it checked out at a bicycle repair shop.
what type of insulation did you use ? if it was cellulose then it has settled
