How to reproduce:

Open the game

view all the content in the market place that has the green new tag

close the game and re open it to get rid of the new tag (this itself is a bug and its number is mcpe-31998 )

close the game again and then turn off wifi/data

reopen the game and wait for the game to "log in"

After it "logs in" close the game

after closing the game turn back on wifi/data then reopen the game

then the green new tag will be back