After inserting the tip of the filament into the ams input slot, pull the button back slightly. The same button that you push in order to insert the fillament. Sometimes the button sticks forward slightly which doesnt allow for a good bite. Push button forward, insert filament and pull button back. If this is the issue, youll notice movement in the button when you pull back.
I don’t push the button. Just push the filament in until it grabs and feeds, and just pull it out to remove. I’m probably causing some additional wear on the rollers that drive the filament, so maybe this isn’t such a good idea for someone who does high volume printing. But not touching the button ensures it won’t get “hung” in a partially disengaged state.