[The5thElephant]

Or maybe you just have some aphantasia?

My visual imagination absolutely can have a time dimension just like my audio imagination. I can remember sequences of film from movies I have seen many times with high level of detail, and then if I so choose change what happens in that sequence to whatever I want.

I think it's more that as humans our audio fidelity in general is less detailed than our visual fidelity so it is easier for us to notice limitations in our ability to imagine visuals than in our ability to imagine audio.