S8+ gallery doesn't show up in any apps

[AC Question]

I switched from an iPhone 6 to the galaxy S8+. Did the file transfer from phone to phone. Now on the S8 none of my pictures show up when trying to post from an app ie. Facebook, instagram, messenger. I even tried taking a new picture and seeing if maybe my old ones were not accessible. Nothing shows. The only way I've been able to bypass it is to go to my gallery select the photo then share then choose the application. After I post the photo then and only then does it show up in the gallery for that application. I'm all outta ideas as this is the first android I've had.helppp