This is interesting - if the sensor is a ON / OFF type - and not a motion based one - this may well indicate either a faulty sensor, or the level setup is incorrect in the configuration.
Normally, the problem we see for wiring etc is that the signal is reversed - but if both with and without filament produce TRIGGERED as a status, then there is no way we can detect what’s going on.
Is it possible that the sensor is a rotary encoder type sensor which sends a pulse as the filament moves?