Since I have never had any feed problem until just recently, obviously something has changed, which brings up the question, why does it feed normally if I push up on the magazine?
Since the problem seems to be magazine related, the change almost has to be with the magazine...and since the magazine(s) is/are undamaged...the spring would be the most likely culprit, since it's the part most subject to change with use. The next suspect would be the follower angle.
As to why it feeds when you push up on the magazine...*shrug*...who knows.
Try the EGW mag catch and see if it cures it. If it does, be happy.