Custom fonts not working

I’ve hit a problem with text elements: I can’t use custom fonts.

I can upload a custom font, and it appears to work fine in the creator and the preview. When I save it, it shows up in the app under “My Designs”, but when I send it to my watch it displays either whatever font I had the text set to previously, or the standard Roboto font. It never uses the font I upload. (2nd gen. Moto 360 running 6.0.1.)

Moreover, regardless of what font I subsequently set the text element to, it continues to use the same font. I have to delete the text element and create a new one, and pick one of the standard fonts offered by the online creator.

If I return to the creator later (I suspect after rebooting my PC – I make a habit of shutting it down every night), the font I uploaded is still listed in the font picker, but displays in a generic serif font (looks like Times New Roman); however, on the watch it displays as the standard Roboto font.

I initially thought I was using a font with licensing restrictions, but this doesn’t appear to be the issue.

By the way, is there a way to remove custom fonts? I’d like to experiment some more, but I don’t want to clutter the font picker with unusable fonts.

A similar issue here. I use various built-in fonts in the watch face creator. They do not show up on the watch. LG G watch here (original).

I also have the issue where the built-in fonts don’t work. Moto 360 1st gen.