Something wrong with faces messing up subdivision surface

Something is wrong with my model (a few faces are more opaque) and it screws up the subsurface modifier. Any thoughts?

normals, normals dude, always recalculate normals for subdiv!!! flipped normals is a subdiv weakness…
and you have some ngons there, you should fix them (use knife tool to redirect the topology, inset, bevel, grid fill, bridge edge loops, or loop cuts), or inset that ngon to avoid less stretching in unwanted areas (in flat and small areas is ok)

Thanks so much for the help! The normals fixed that problem. I have scoured the object and can’t find any ngons. Do you see any?

Ah! It was the plane on the bottom. Figured it out. Thank you so much!