Firsrt time with this issue. I mainly use the external spool but i have an AMS1. I removed filament to change to another. I went from ASA to PLA. Extruder and nozzle are 3 months old. Printer is 10 months old. When i loaded the PLA it felt blocked and the screen acted as if i never pushed filament in. Next i removed the Extruder and hotend and checked for clogs. Nothing there. Clean path. Replaced in printer and tried again. Same behavior. Could this be the filament sensor or the board in the tool head with all the connections? Im at a loss. Any help would be great.
The wiki has information on how to check/test the sensor.