The page says that “browsers may split a QR code across lines” - but this isn’t split across lines.
Experimenting, if I just type "[Q R]" (very short, so not likely to line-break), the problem still occurs.
If I inspect the element, and add `white-space: nowrap;` to its style, the problem still occurs (although the text doesn’t wrap!).
Or was that text added since you viewed it?
I’m still not sure if this is the mentioned issue or a different one.