I’m trying to help a friend by introducing him to compound semaglutide. I found him a website with a good price and directed him to Amazon for accessories. He’s about 6 injections in and complaining that he’s unable to depress the plunger to dispense the medicine. I’ve had issues like this when Luer lock needles weren’t screwed on tight enough, but this is a one piece syringe. Any ideas what might be going on?