This is a weird one.
I tried searching for "1910" and instead of going to the search results, I was redirected to question with id 1910 instead. I tried searching both from the header search box and the search page, and even typed the search url (history.stackexchange.com/search?q=1910) manually, but without success.
Searching for "1920" and every other year I tried works normally. I couldn't reproduce the bug on any other SE site.