I like this machine but I seem to have to level the bed often. Anytime I print something I have to go through the bed leveling process. Sometimes twice during a print job. I can level the bed with the provided paper. Then start the print job. I then notice that there is no filament extruding so I stop the print and re-level the bed. Seems the nozzle was touching the bed enough to block the flow. Don't know why as I just leveled the bed!

Will I really need to do bed leveling this often? If this is normal it's kind of a pain. If this is not normal, what can I do?
Thank you for your help
Bill