It could be a number of things, I would start with visualizing the collisions or looking at the IK setup. Let’s start with some debugging of the collision.
Get into that same position in the pic. Eject from the game by pressing F8. In the top left where it says, “Perspective” “Lit” and “Show”, click Lit and select “Player Collision”
Is there a collision inside your box collision (a green, pink, or violet shape)? Can you click on it and see what it is in the outliner?
Note: Holding 'CTRL + Alt` while hovering over “Player Collision” selection will show the color legend.
Collisions can be changed on static meshes by finding the asset in the content drawer and opening it. Near the top left is a Collision drop down. Click it, and select remove.
Let me know what you find