How to access saved files

Ok so on phone #1(all phones are Android) I had my boy emulator and a bunch of Pokemon games. I saved the Roms on an SD card and did in game saves and everything was fine.

Moved on to phone #2 transferred SD card and continued playing everything is great.

Phone #3 I did same thing and everything works all games can be accessed at most recent save point.

Phone# 4cant access anything saved from phone 3. As far as I can tell I didn't do anything differently this time. How can I access my saved files so I don't restart thing over? Thanks guys.