The non-lore answer to these sorts of contradictions is usually that the author just did not take it into consideration. Like when two people are in space and are able to speak aloud to eachother even though there's no air to transfer the vibrations.
In situations like that, I am a bit put off by the idea that we should take it upon ourselves as the audience to imagine a solution like "maybe they have special powers that allowed them to communicate verbally in a vacuum." As far as this specific scenario is concerned, "GP adding space and time to this realm" resolves the contradiction, but is there evidence of him doing that? Like, genuine actual evidence that he did something like "added space and time" to a void, or are we taking some incredibly vague scene and saying "well, despite appearances, this non-descript action simply MUST have also added space and time because otherwise the story doesn't make sense!"