When creating PDFs, avoid using "Print to PDF." A screen reader user may still be able to access the text of PDFs created this way, but heading structure, alternative text, and any other tag structure will be lost. Using "Save As" or "Export" can preserve these tags.
@A11yAwareness Noted! I'm curious whether all print to PDF implementations do it that way? Is it a technical limitation or something that can be fixed?

@tarakiyee Good question. This WebAIM post gets into more detail, but it seems to be more than just one or two programs.

https://webaim.org/techniques/acrobat/converting

WebAIM: PDF Accessibility - Converting Documents to PDF