Corrupt collision channels? [4.14]

Few days ago the editor crashed and I didn’t notice anything at first. But yesterday when I was doing some tests for different things, I noticed my character could clip through objects/characters/platforms but only sometimes.

EDIT: It seems like all objects set to ‘movable’ mobility will allow me to clip through them when this happens. No matter if it has physics on or not. Is there anything different about movable objects collision?

It’s so incredibly inconsistent. Sometimes I can play the game 10x times without this happening at all. Sometimes it happens immediately as I start but goes away in a few seconds, sometimes it doesn’t go away until I stop and re-play. It’s driving me mad.

I mean, if it was more consistent I could eventually, hopefully, find out the issue but since it’s so random I have no idea whats going on and this wasn’t a problem just a week ago.

I’ve made sure that the collision channels on both objects are set to block each other. I’ve even loaded older character .uasset backups with no luck at getting closer to find out the problem. I’ve tried re-setting the collisions/object types and after testing a few times with no issues, been sure that it’s fixed only for it to return in an hour or two and I’m absolutely lost at whats going on.

Here are some screenshots:

Here I can just walk right through the polar bear npc, right after starting the game. Both characters collision is shown there, both have pawns set to block, and both are pawn object types.

Here’s a blueprint loop I made that starts immediately as the character spawns, just to make sure the channels weren’t being turned off or switched or something. Everything seems fine and is set to block:

Suddenly, 3-10 seconds later (it varies a lot between tests) everythings working and I get pushed out of the polar bear, sometimes this doesn’t happen at all :

This not only happens with characters, but also random meshes/objects (which have the exact same settings as the floor) but the floor always remains blocked. I’m absolutely lost here.

After further testing, it seems to be collisions between all objects with mobility set to Movable will just turn off randomly for a few seconds.

I’ve tried using basic cubes, setting them to movable (physics etc off, only thing I changed was setting mobility to movable) and I’ll be able to walk through them, then after a (seemingly) random amount of time, I’ll no longer be able to do so and everythings ‘normal’. What could be causing that?