PR 25.4.0 introduced a new default subtitle and font preference: Edit -> Preferences -> Graphics -> Default Subtitle and Text Font. But that is all it says in helpx:
"Set your preferred default fonts for text and subtitles."
I just tested in 25.4.1 on Win 11. I left the preference default of Lucida Console. I get that font if I create a caption track with no style included. And if I use the text tool, it appears "Sticky," type one text entry and set a font, that is the font that comes up the next time. That continues as long as PR is open even if I change projects. But if I close PR and reopen, a new text instance has a font of Minion Pro, not Lucida Console.
I also tested in Beta 25.6.0.39. There it behaves correctly. If I have not changed the font during a PR session, the text tool creates text in Lucide Console. If I change the font, it stays changed until I change it again or PR is restarted.
Stan