When the gamemode get's changed by command blocks, shows GUI but doesn't update actually

for example: Changing gamemode from 2 to 1 causes the player to
get the ability of flying BUT can't break blocks. Only
ghost blocks, where you can't fly through

anotherone: gamemode changed from 1 to 2. No avildamage,
when setblock from command high in the air

Hope it get's fixed soon

SINGLEPLAYER!