I always end up in +1 CL even in the cup I see a lot of higher level players (usually bottom half teams but also stronger teams). My team usually has bean around 113% at the end of the last seasons and I guess when you are above 90% this happens, it pairs you with 70%-80% teams of a higher level. I also noticed some friends in the same level as mine but with teams around 70%-80% have easier league opponents. That's just my experience I don't really know