I was making a custom map and made it to where in the lobby you are in Adventure Mode but 5 seconds after the game starts switch you to Survival Mode. However when I do this most of the time on the client it shows the blocks break but not on server side, unless you use an item that can mine that block for Adventure mode.

Edit: the world I used to reproduce the bug(may take more than one attempt): https://www.dropbox.com/sh/305grtkyjxvyb36/Xz5RCsRfD_