All just some info to share, and perhaps some venting too.
I have recently uploaded both my latest book manuscript and cover to IS. After an initial change to the cover format - all was accepted by IS. However - it took them 6 days to finally come back to me with their acknowledgement that the book has now been accepted, and I could finally enable it for distribution - meaning shortly it will be on pre-sale. They could not tell me at all when to expect that to happen - in fact their advice was to keep checking the various distributor platforms to see when it gets listed.
So - FYI - build extra time into your schedules when working with these guys.