Im having the same problem. It occurs in the mesa level underground when you have to climb a totem pole to reach a rope to slide across. I jump across and am hanging by my hands but no matter how hard i push the space bar it wont climb up. I even used to left shift key to hang off to jump back but it wont jump either. Only way to get off the totem pole is to press C to crouch and i drop. It is climbable cause my teammate (AI) jumped across next to me and climbed up. bug?
For most of you I guess it's due to the protection triggers from using a nocd fix, first one was the rope slide in the first level (Was fixed by a updated nocd.) and the second trigger is shortly after that when you need to climb up a wall using a set of ledges, no fix currently aside from using the disc.