Have no interest in your reddit thread. Your photos for the most part are just not helpful. May not matter a lot, but what are the make/model of the speakers?
P1 P2 may be a computer thing, don't know, never saw that designation before, seems a
P1 is a TRS type, P2 a TRRS. Don't use the analog outs of a pc myself in any case, altho with a correct cable you could use the analog headphone outs from a computer. I assume you're connecting a computer or maybe a phone/tablet to the receiver? Or some other type of audio source? Some clarity with the device you're connecting, with what type of cable, to which inputs on the receiver would be helpful.
FWIW if the receiver is repeatedly shutting down in protect mode, with nothing attached, it may simply be defective....if doing it with speakers attached it may indicate a short.