PU troops bug

I've started a Poland game recently and quickly got Bohemia PU so I took PU over lithunia in the event and took hungary since Austria decided they wanted no alliance no more with them. Since then I sometimes see those troops bug out like standing nowhere for half a war or Hungary basically deleting every troops after war (they have loans maybe that's why) but my Burgundian PU did delete all it's troops as well so I don't really know. Does that happen to you guys as well ?