If you do the add host to a group element, as soon as you press the āprocess changesā button, and scroll back to the top of the page, Iāll bet you see the āLoader barā telling you āGroup created successfullyā or something similar.
The loader is only present for 5 seconds.
The idea of the move to ajax in case you must ask is so you could process many hosts in one sitting area rather than have to recycle the load time every time you click process changes.