So, i'm thinking you're big into vocal melodies, strong chord progressions, and more traditional scales/time signatures (although Sleep Token have some complex ones). The fact that AdP doesn't have a singer, uses microtones, toned down the heaviness, and play in odd time signatures are probably keeping you from sinking your teeth into them. You kind of have to imagine the lead guitar loops more like lead vocal lines to be able to see where they fit into the songs.

This is quite remarkable: I thought you might just not like prog-rock, however you say you like Periphery, which I can't stand for their noodly approach, just like Polyphia (with the annoyingly similar name too). It might just be that all the bands I listed above, and Angine de Poitrine too, are for people with ADHD.