So, I'm running Interstellar on an FLX1s phone; it's Flatpak, too. I don't mind the flat emojis at all, but most of the emojis for me are missing and show only boxes. Many user names are also blocks. It's absolutely a font issue... so how do I fix it?

Flatpak is a constant source of breakage on this phone, and I figured out the last thing that was causing apps to not launch, but it was a painful, annoying journey. What's the magic incantation to make Flatpak give apps access to the fonts they need?