hey, I’m wondering how you only rotate the parent without rotating or affecting the children in the editor not during runtime, thanks 
Check out this answer
Make sure you have saved the scene… then you can try… 1) “create empty” top level temp Gameobject 2) drag the children onto the temp object (so they are no-longer under the parent 3) Move/rotate the parent 4) then after drag the children back onto the parent 4) ( p.s. can now delete the empty again temp…) long winded but works,