Hmm... That doesn't help. Those vectors are definitely fine. Yeah, code is fine. Not sure why you changed
infinite_inertia to false but it shouldn't make a difference. I guess that was during debuging.
Ok, go to the debug menu and choose "visible collision shapes" - this will let you see the collision shapes in runtime, in case there's a weird protrusion of something. Check for overlapping. Iso isn't x to y symmetrical, there's twice the angle up than there is across.
Try printing the collisions (with
get_slide_collision()). Maybe they have weird normals or something.
Make sure that the walls aren't colliding with themselves. Check the mask/layers.
If the collision shape is a box, try it with a circle and see.
You can tweek collision settings but I'm reluctant to tell you to do that, the default is generally fine.
Oh! Check the camera. Make sure that isn't the cause / no snapping / no limits / no floor / round / etc.
Sorry I wasn't more help buddy, I'm genuinely not sure.