Text disappeared in Illustrator 29.2.1 after reopening file

A couple weeks ago, I created a two-column page with text in both columns, successfully exported the file to PDF, and then saved and closed the file.

Today I opened the .ai file to edit, and the text in the left column is invisible.

When I select the layers I see underlining suggesting lines of text are there, but I don't see the text.

The layers have visibility turned on, and when I looked at Overprint, it is deselected.

I also tried opening the .pdf that I had exported from Illustrator a couple weeks ago, and there too, the text in the left column is missing.

But when I open the same pdf in Preview (i'm on a Mac), I can see all the text in the left column.

How do I fix this?

I'm running Illustrator 29.2.1 on Mac Sequoia 15.2. 

Thanks.

Screenshots:

1) Showing the green highlighting of invisible text. 

2) Layer settings. The missing text is in the top green layer. Moving the layer's position doesn't change anything.