Cannot open command blocks in creative mode after dying

Any time I die, whether it be from a zombie or /kill, when I respawn I am unable to open any command blocks when in creative mode, as if I were in survival mode.

I first noticed this bug on my friends server, but it also occurs on single player (made a new world just to test it, and it still happened).

The only way I can fix this bug is to re-log from the server / single player world