Thank you, both. Under Alfred Preferences > Features > 1Password, in the lower left corner, it does say "Loaded 306 bookmarks". I was just about to create some screenshots of it not working, but now it's working! Maybe the computer or some service had to restart for something to display as expected. Anyway, issue resolved! Thanks again for your support.
When I get the Alfred window and type '1p ', the interface changes to look like it's going to help me "Find and open a 1password 1Click bookmark", but no matter what I type next, no 1Password results come up (and I have over 400 login items). It just kicks me back to my failover search options. Suggestions?