EDIT:
Never mind.
The problem resolved itself.
See edit below.
Starting today (or maybe yesterday), eBay’s search is now screwed up.
This search worked yesterday, but it doesn’t work today.
I don’t know what the new proper syntax is, and I hope that eBay reverts to what was working yesterday. 
EDIT:
Right after I created this thread, now eBay search is working properly. 