In review, I'm told there are 3 suggested edits for me to approve/reject/improve:
(These images are from the old review system; the new system's interface is different but this still seems to occur.)
It looks like that when I am on any tab except the suggested edits tab itself. But when I switch to the suggested edits tab, so that I can review edits, there's nothing there:
I switch back to any other tab, and I see that there are 3 suggested edits again. I switch back to the 3 suggested edits tab, and they edits are gone. So this is not caused just by the edits having been reviewed by someone else.
This does not appear browser-specific.
Update: jokerdino has pointed out that these 3 suggested edits that I cannot review were my own tag wiki edit suggestions. That clarifies for me why this is occurring, but it still seems like a bug. Shouldn't the number of suggested edits listed in review for any user be the number of pending suggestions that user can review?
Please note that this will only happen for users with at least 5,000 reputation and less than 20,000. This is the rep range in which a user can review a tag wiki edit but cannot make one without it being approved.