Earlier today (or at least a couple of days ago) the review queues had numbers showing up indicating how many reviews were pending in each. Those are now missing, and there's no indication of which queues have how many reviews:
(This screenshot was taken with all userscripts disabled.)
Some of these queues have reviews pending in them for me to act on, but no indicator is showing up at all. I clicked this menu because its icon was orange, and I visited all queues and there were two queues with one review each in them.
I could not tell from this dropdown which queues needed my attention though, and if it's trying to get my attention to the review queues, it really should tell me which of them actually need my attention.
Also from meta.se just now (icon orange):
(There's some earlier discussion of the review indicators being removed in Where are the review queue counters?, but this doesn't appear to describe a bug about the indicators going missing even when there's reviews.)