I am new here too - also have a new TX22. Have about 500 through mine and have not had failure to lock on empty or to lock with rounds still in a magazine. But premature lock back could be caused by a weak slide stop spring which allows the slide stop to jump up during recoil. Of course 22lr is not snappy. I am handling my TX22 with slide removed and working the slide stop. It feels like a very light spring, maybe yours is just a bit weak. Mine is a little gritty but seems well fit between the plastic frame and the fire control housing.