I also found this solution but you cant use the photo club if you do this : For anyone hving trouble with the Alola Photo Club: Yeah, I'm playing on Citra as well and, like all of you, had that issue. However, I didn't wanna use someone else's save, nor wait for someone to do research on this, so i did it myself and solved it to some extent. What to do?
-Load your save file on PKHeX. Since you're all playing on Citra, I doubt any of you guys don't know how to use it.
-Open the "Event Flags" window.
-Go to the "Research" tab.
-Look for constant 68, and set its value to 410.
-Look for constant 470, and set its value to 8730.
-Obviously, save the changes. Once you load the game, it should behave as if you'd already done that Photo Club thing.
Rotom should be telling you to go to Big Wave Beach, and if you enter the club, the clerk shouldn't force you to do the photo thing anymore. This solution is not perfect, though, for the following reasons:
-While you'd normally get a "Photo Album" icon on your menu, it won't appear if you do it this way (who cares, anyway?)
-When you get to the beach, Hau will talk to you, but his overworld model won't appear, so it'll look really awkward. This, however, solves automatically once you reach Akala.
-Haven't found any more side effects, but if I do, I'll let you know. DISCLAIMER If you do anything stupid and get your save corrupted, I'm not gonna take any responsibility, nor give a heck about it.
Do it at your own risk. Backups are recommended.