Please note that AI does make mistakes. Quite often actually.
986x720 IS 720p.
The problem is that what is being downloaded is not the resolution it says it will download.
Yes, the Google AI info took this way off. When the SF download window pops up, it says 986*720. Even while downloading, it says 720, and that's what most would think they are going to get.
Instead, it gets 790*576.
So OP may have to accept this, as I highly doubt SF sees this as a high priority to try to fix, if it's even possible to fix in SF, although it is a bug in SF.
As shown in the screenshot by
zettimetti.