I have noticed since the promotion and theme change, the outstanding review count is not showing up in the ribbon (well, that's what it's called in the MicroSoft SharePoint world ... the black strip at the top, to the right of your badges). I didn't know if this was a known issue since the promotion and was being worked on, or if nobody had really noticed this? Just throwing it out there.
According to this answer on the related question on the main meta, for users below 10k reputation the review counter only shows the number of pending "Suggested Edit" review items, not the number of all review items you can act upon. So the number can indeed be lower than what you can actually review. It is not entirely clear why this is so, but it's apparently by design.
If on the other hand you reach 10k reputation and get access to the full moderation tools and the full review queues, the number starts to show all items in the review queue, including the ones you already acted on. So then the number might actually be higher than what you can practically review
It is appearing for me.
And I've confirmed that there were a total of 9 items in my review queue.
Can you confirm you have items in your queue (as you seem to have reviewed items today, perhaps there are no items in your queue at present).