Something appears to be wrong with search in chat and on main.
There's roughly 2 million posts containing "thanks" on Stack Overflow. Search claims there's none. The same on MSE - search yields no results regardless of what the search term is.
Chat is not doing specifically better - any searches there throws an error (the standardized "Something bad happened" - no details on my end).
Possibly related, while writing this question, no "similar questions" were loaded, and the related questions in the dropdown loaded forever.
What's going on here? It started happening recently, and it's reproduced by several people in SOCVR. I haven't tested more than SO and MSE for main site search, but all the chat sites throw errors when searching.