steveishere55569 Update: I've figured out what's causing this particular issue.
This whole time I thought it was some kind of layering or scissor box issue that was covering the text, but instead it turns out to be a simple color issue. They changed it in a recent snapshot so that text color now has an alpha channel. All it took was adding one and now the text shows up again.

So this should be fixed in the 25w20a build, provided Mojang doesn't do something crazy that instantly breaks it again. (Has happened before.)