I loaded up my old world and found that all my chests were empty and the wall I had my maps on was also empty. I didn't have anything in my inventory either, so I had to start from the beginning. I made new item frames and put them up on a wall and started to gather new maps of the area I was in, but every time I left the chunk I was on they weren't there when I came back. When I broke the block I got the maps & item frames back but the same thing happened again once I placed them.

To replicate the bug first put up item frames with maps in them. Then fly a few chunks away from were you put them, when you go back they're gone.