Not letting the bit cool-down between holes combined with the bit being stuck combined with drilling at too-low sped thus too-high torque. Typical problem with cordless impact drills as they have a too-high torque at the lower speed setting.
When drilling to masonry with PDC, use speed 3 or 4 (low torque) and let the bit cool down between holes. If you want to drill at lower speed, still use speed 4 and regulate the drilling speed by the trigger.
Ref heat, when drilling masonry I have a cup of water around and cool the bit after every hole by a short drop in water. When on a ladder, I would just put a bit of spit on it by finger, just to get it the