Interesting, it seems to work fine if you place the block base point at 0. When I pick another point by snapping to something, the text doesn’t print.
Two blocks in this picture - the only thing that is different is the base point.
But then it gets silly. I turned on the points of all of it and then moved it all closer to the origin. When I try to print to PDF, things look like this:
@stevebaer, partially related, perhaps. When exporting to PDF, I got the preview to show the text in the block but when I opened the PDF file, the text was not to be seen.