Ctrl-F1 shortcut stopped working in SSMS 2014

I've had the Ctrl-F1 query shortcut bound to sp_whoisactive for years (this technique is described in https://dba.stackexchange.com/questions/16182/how-to-assign-ctrlf1-to-sp-whoisactive-in-ssms-2012) . A few days ago, it stopped working. If I hit Ctrl-F1, SQL Studio now launches Books Online in Internet Explorer. Has anyone else seen this problem? Is there a fix? I confirmed that the shortcut it still set. Changing the shortcut does not fix the problem, Ctrl-F1 still launches BoL. Cycling SQL Studio has had no effect. FWIW, this happened after IT restarted the server while I was logged in, so SSMS did not shut down clean. I can of course use another keyboard shortcut (though sadly it seems Ctrl-1 is hardcoded to sp_help), it just bothers my OCD to use a different shortcut for the same command on different machines.