This is a single line of something or other. 19.5px is too short. Removing my height attribute fixes the problem.
Interesting that one. Looks like a very old bug actually. That height was done via JS, but the logic had a comparison of a rounded number to a non rounder number, so edge cases (single line) were being set incorrectly.
Should be fixed now, browser refresh required.
You had me worried there for a second, but it also seems to look fine without JS.