Careful, my friend.
This setting is only valid in Gesture mode and Active track...where HP will be updated every 15 sec.
Any other mode, you need to update your HP manually.
Also like to recommend the advice of fellow forum member "Mr Geek":
"Do not use Dynamic Home Points unless you have full, unfettered access to any point your drone could land along the route flown and you feel you could find it in the landscape type" (re: post)