For me, at the 'choose an action' I have a blue icon with a white arrow for 'files'. I choose this & it takes me another selection dialog where I can choose one of my photo galleries.
I'm on android and my options are camera/camera/files. No help to you I agree all I can assume is your phone's had an update and buggered about with where stuff is found.
Good luck op
OP have you tried choosing one of the other options at the choose an action prompt? It could be you've updated something that has 'conveniently' renamed your photo folder for you.