So, I just Alt-dragged in a new MOGRT for a vertical nameplate to replace a horizontal layout (it's a series of new hire videos shot in varying aspect ratios) and it asked if I want to replace all instances with that layout.
Of course I said no because most are horizontal and I had already set them up.
And then I saw that all the nameplates had been replaced anyway.
And all the names I had entered were wiped out, back to default status.
And I can't undo that.
I restarted Premiere. I tried it on the horizontal and vertical. I tried saying Yes, or No. Doesn't matter, it's all Yes.