I logged out, then back in, and the problem went away. I could still answer the questions if you'd like, but I don't know if there's a point anymore.
Antialiasing looks like its off in several places in the latest version. Both the input text and non-highlighted results don't look antialiased, but the highlighted result does look antialiased. If it's helpful to know, I do have the "Reduced transparency" feature enabled in the Accessibility Preferences and I am using a non-Retina screen. Alfred: v3.8  macOS: 10.14.3 (18D109)