In The Day of the Doctor, Gallifrey is shifted into a pocket universe to escape the Time War:
WARRIOR: Gallifrey would be gone, the Daleks would be destroyed, and it would look to the rest of the universe as if they'd annihilated each other.
CLARA: But where would Gallifrey be?
DOCTOR 10: Frozen. Frozen in an instant of time, safe and hidden away.
The idea that the entire planet is frozen in a sort of time lock is clearly demonstrated again:
GENERAL: We'd be lost in another universe, frozen in a single moment. We'd have nothing.
WARRIOR [on monitor]: [...] a single moment in time, held in a parallel pocket universe.
So, Gallifrey and the Time Lords are frozen in the pocket universe.
But then, in The Time of the Doctor, we learn that Gallifrey is communicating with the universe via the cracks in the universe:
TASHA: They blew up your time capsule, created the very cracks in the universe through which the Time Lords are now calling.
And then, in Hell Bent, we learn that the Time Lords have actually returned to the universe, albeit stealthily to avoid all-out war:
GENERAL: Gallifrey is currently positioned at the extreme end of the time continuum, for its own protection. We're at the end of the universe, give or take a star system.*
Have I missed something? I thought Gallifrey was "frozen in an instant of time", but this doesn't seem to be the case. My question is: how could the Time Lords return to/communicate with the universe by their own means if they were frozen in their pocket universe?
One could argue that "frozen" isn't to be taken literally, but the War Doctor clearly states that they are using stasis cube technology to freeze the planet, and, as seen in the "Gallifrey Falls No More" painting, time—as well as everything else—is very literally frozen where stasis cubes are involved.