Everything is working as intended. The magazines are most likely full when you insert them into the frame. The top round of ammunition is putting pressure on the slide stripper. When you push on the bottom of the mag you are feeling the pressure of the rounds compressing further into the mag. The click you hear and feel is the sound of the MR fully seating into the mag recess.
Lock the slide to the rear and insert the mag. You will notice it takes a lot less pressure to seat it!