I stumbled upon this post because I am facing the same issue. I agree this seems like a bug. I am not using fontbase rather a PowerShell script to copy the TTF file to C:\Windows\Fonts, make appropriate registry entries in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts and then Copying ACLs of a pre-installed font onto the copied font.

This works for me on Windows 10 (22H2) but on Windows 11 (23H2) all the apps that query DirectWrite (like browsers) are unable to detect the font after the installation. It gets detected by apps using GDI like MS Word, Notepad++.

To the resolve this, I had to reset the FontCache on windows:

1. Stop the "FontCache" service. Stop-Service FontCache -Force (You might need to disable it temporarily since it gets started automatically in few seconds)
2. Delete the FontCache folder: C:\Windows\ServiceProfiles\LocalService\AppData\Local\FontCache
3. Restart the FontCache Service and the application (in my case the browser)

I am still confused as to what changed in Windows 10 vs Windows 11 for mechanism of Font installation that would cause this.