UE4 - AI's stops walking after unloading and returning to Level, why?

Hi, I created this level, once I get inside an overlaper, it loads the level, all charaters inside work well, they walk without issues, but… If I get out form that level, Unload Level, and return, load it again, AI’s can’t walk (they only run the walk animation and rotate in place), at this point I tried everything, I created a navmesh inside Persistent Level and sub levels, changing Runtime generation from static to dynamic doesn’t work, Force rebuild on Load doesn’t work, not any collision is affecting Navigation, crown manager is ok and very high like 5,000 and the most weird part: If I load that level with 10 actors, the 10 walk well, but after unloading and loading again, 5 out of 10 do walk…

Please help ASAP!!!:frowning: