Custom glyphs don't display in certain apps

I’m extremely new to fontmaking and unicode, but I’ve been trying to put an alphabet of runes into my private use areas and it works in applications like Word and Notepad, but not in Chrome or Discord. Does anyone know why this is, and if possible, how to get my PUA glyphs to display properly in such apps?

There is a Unicode block for runes. Don’t put it in the PUA.

Tip: download the free app Unicode Checker it will help you find the right Unicode values.

And for testing in browsers, use websites like fontdrop.com or the mekkablue script Test > Webfont Test HTML. About extending the app with scripts, read the Extending Glyphs tutorial.