Ok, to isolate the issue I’ve made the simplest possible set of blueprints from scratch with some debugging.
Here is character blueprint
It simply calculates direction vector from actor to mouse hit on the ground plane. We draw debug arrow in green showing that direction. Then we update actor rotation accordingly.
This works as expected
Animation blueprint simply plays idle animation. In update animation event I get the rotation and draw pink arrow to see it visually.
The result
You can see pink arrow pointing 0,1,0 (default rotation not updated)
Casting to character blueprint is not relevant here because we only use default methods on base actor classes and do not need to access custom properties.