@chuck @sungo Under-extrusion? Filament not the right volume per length (eg: oval, widest as expected dia, but thinnest less than expected), or something else slowing down the amount of plastic it expects to push out (eg: extrusion multiplier wrong, skipping extruder steps, wrong number of extruder steps/mm, etc).
Consider this a friendly, local pub. Make yourself at home, bring your friends, have a good time! Meet new people, have a laugh, enjoy the ambience, and the Oxford commas.