I found a fix.... Was doing it on my lg v10 after editing photos in the gallery app already installed on my phone. What I did was after editing my photo I saved it and when it went to the picture where you can choose share, edit, etc. I clicked the three little dots for the menu and it lets you rotate it I rotated it 90 degrees to put it in landscape then rotated it 90 degrees back to vertical and it worked I uploaded to facebook and sent it in a message (when before it was sending the pic in landscape mode) now it sends correctky.....
Hope this helps