Thanks, I already followed advice in that exact post, I even made a screenshot to document it when I installed the fonts. Here it is,
My possibly faulty assumption is that since I can use the new font in a popup, it should be available to any program running on that machine. That's why I included that comment in the first screenshot.
I followed some other post regarding using custom fonts in popups so that I could see the new font really is available. I did that by editing the HTML, like this
When I publish from ArcPro, it gives a warning that my doc has special fonts and that they have to be installed on the server. Too bad it does not check instead of issuing the warning. My guess is that they just remove unexpected fonts during the publishing process and that once again, it is a confusing and erroneous warning message.
My browser can display the Shadow font so I know it's able to display Shadow. The problem is elsewhere.