It's hard to tell, but if these are exposed edges, then a bullnose/trim/pencil is how it should have been finished and not just grouted. Sooner or later that grout will crumble from that edge. Here are some photos for reference. Notice the trim piece in first pic---it is finished on the outside edge. Second photo is an example of how a pencil trim was used to finish the edge. Keep us posted with your dilemma. Good Luck!
[houzz=][houzz=]