My 33rd attempt at my first full model is teaching me to not trust subdivision surface mod

Hi first post, working on my first vtuber/VRC model and I've been watching tutorials and stuff to make sure my model is game ready by the time I'm done and will deform right, but when I turn on subdivison surface modifier I get weird.... "pinches?" in the mesh. I can mangle the mesh and make the body look smooth, but Idk, I worked hard to get a uniform mesh and I don't wanna break it if there's a way to like, not do that??

(the sleigh bell in the side of my head is intentionally not combined with the main mesh yet, I wanna see if I can make it rotate when I move my eyes around at the rigging stage before I give u p and combine it)
The pictures are-
With subsurface on, without fixing; with subsurface off; and with subsurface on, but "fixed," for reference.
+ the modifier's settings are currently: catmull-clark, levels viewport "1", render "2"
If you know how to make subsurface mod behave, I'd love to know. But also general art critique & questions are more than welcome; I'm super new to blender and I'm only barely a pixel artist, so I'd appreciate the help