In your case, the Schluter or similar edge trim would have been the easiest option. To mitre the installer will have to remove both sides and redo. Ask him if's he OK with doing mitre edges or rethink the edge trim.

IMO bullnose tile is a dated very traditional look can we see the rest of the shower ? IMO if the bullnose is already there why were the corners not done the same I need a better idea of the whole spac e.

I don't think it's bad.

I did ask them to mitre the corner (for an addtl cost) and it looks much better. I won’t be able to avoid it at the shower corner though. Lesson learned….I’ll know for the future to use schluter trim or go with a tile without a pattern direction. I do realize many think bullnose is outdated, but I just preferred that look (until I realized the impact it has on a corner). Thanks all for your comments!