On Linguistics.SE, I observe Pending Review items counter stuck. This happens only at this site¹ and it never recovers for several months so far, while I occasionally check these items and submit my reviews.
The following links are full screenshots taken at Review page and 6 individual history pages.
(1),
(2),
(3),
(4),
(5),
(6),
(7)
(¹) Since 2014, it started happening on Politics.SE and several other sites; I failed to find any pattern.