intermittently won't spin

Hi. The first thing i would do is check for stored error codes. Typically on Frigidaire front load washers this is done by pressing and holding in the start and cancel at the same time. Give it about 3 seconds and there should be a E followed by 2 numbers in the display. This is your most recent error code. The tech sheet on this unit should be located under the top panel. Remove the 2 or 3 screws in the back of the top panel and slide the panel off. The tech sheet should be taped on top of the dispenser. My guess on what could be causing the unit to not spin sometimes is a clogged drain pump or something preventing the unit from draining the water out. I would check the drain system first. Also, a faulty door lock could cause this as well. Attached is a link to the door lock as well a repair video.