So here is the bug :
As you can see it looks like some vertices are unaffected by the subdivision modifier.
The same thing seems to be happening with the bevel modifier.
I created this object with booleans modifiers (which I applied) so it may explain why it is deformed. I tried merging vertices by distance (it fused 6 vertices but still didn't change the output). I tried applying all transforms (ctrl+a). I tried moving vertices around. Nothing worked.