It might be a glyph cache thing, not sure why it would happen though.
We did update from uncompressed glyph, to compressed ones, but I’d assume that all glyphs would fail then. If it would fail, I believe you’d instead see a garbled glyph (more like noise).
Are you using label.set_text()straight up? Or are you using any other helper functions like richtext?
Of course, it’s really tricky to find without any info other than on a user’s screen shot
In other news, there was this other font-related issue that we’ve noticed happening only on a particular Macbook Pro model (15" 2013 with an Nvidia 650M on macOS), but it seems different. I realised I forgot to report that one as well. It could be a richtext issue. Haven’t seen it happen since I switched to combine_words = true, but it could still happen, since it wasn’t a consistent repro. It’s still odd that it only ever happened on two machines of that exact model, though.