The problem here is caused by the rotational DoF freeze on the player object. Once it approaches the corners of the static geometry, the solver would naturally want to apply rotational impulse to twist the player and allow some forward motion that way, however it cannot due to the DoF lock, so instead the object stays stationary. This effect depends on the magnitude of the penetration into the static geometry -- the more the overlap is, the higher the chance that the solver would also have to apply at least some of the linear impulse -- so slow movements will normally result in a 100% sticky corner. One of the ways to around it would be to have smooth geometry on the player (e.g. capsule), or have custom collision code that would add some linear force around corners to avoid the stickiness.