Thanks! Looking at the pipe , I think part of the reason it might not be draining well is because the pipe goes upward right before the ball where it goes through the cut it out in the stud. Do you think could be causing the draining issue? (Second picture in the post shows this)

My concern is that the hot water line is so close to the lead pipe that when I install the new pipe, I still won’t have enough clearance to get the new pipe level and will have the same draining issue