we might be having the debate about which glide path indicator is primary; ILS or PAPI. My own philosophy is if in doubt ILS.
Both of them become less relevant the closer you get to the ground, they are designed to get you to 200 feet so that you can reference the runway. They stay in scan but become overly sensitive and so from DH in look at the Aim Point and make sure it stays in the same place up and down in the window, if there is an early trend seen from the approach aids make the correction by changing where the aircraft is pointing with respect to the aim point outside rather than chasing the needles or lights inside.
If the ILS and PAPIs are mismatched accept the picture delivered by the ILS at DH and hold it until the flare, it then wouldn't matter if the ILS and PAPIs both failed the approach angle would stay the same.