I started having instances where I could not get a bolt to turn. One time it was a lower control arm under the car. Another time more recently it was a strut bolt. I didn't think about it at the time but in both instances clearance was an issue. So I couldn't physically push on the impact. It removed other bolts in the same location. But not all. So is it possible that I needed more leverage on the impact on the bolt? Also I let the battery run way down and now going to charge it again which I haven't done before.An impact wrench needs something solid to work against in order to generate the high torque for bolt loosening. It cannot generate this torque against something loose or springy (like your hand). The hammer will stay locked onto the anvil and the wrench simply rotates like a drill. Only when it encounters solid resistance (like a lug nut) will the hammer disengage from the anvil and start delivering multiple high speed rotational impacts against the anvil, exchanging its momentum for high torque at the drive end.
In my opinion, it sounds like a discharged battery "it's getting weaker and weaker and weaker".
Good Luck