I have encountered this issue on ID 19.0, as well as the past three prior versions. I am unsure if these two things are related or not, but for no apparent reason, InDesign frequently exports links and form fields incorrectly.
For context, I prepare accessible documents and forms using InDesign. I am building these correctly for accessibility and still encountering these issues.
First Issue: In InDesign, the link will has "shared destination" unchecked and has an alternative text. This occurs with links directing to another Page in the same document - I have not seen this behavior with URLs, emails, et cetera. ("Shared destination" is typically unchecked for accessibility as it causes other errors and leaving it checked has the same problem.) In any case, the link exports with a Tagged Annotation failure in PDF using the Accessibility Checker. When I inspect the link in Content Panel, it's Properties does not display the alternative text.
Frequency: Intermittent and random, but localized to Page links only.
Workaround: Deleting the hyperlink and resetting it in InDesign does not solve the issue. The only solution is to remediate in PDF.
Second Issue: In InDesign, the form fields will be properly built, correctly anchored, all that jazz, and yet for no apparent reason they export as "Tagged Form Fields - failed" in PDF and "Field Descriptions - failed" in PDF using the Accessibility Checker.
When I inspect the fields in Prepare Form > Field Properties, they absolutely DO have Field Descriptions (Tooltips), but they are absent from the Tags panel. For whatever reason, InDesign is not exporting the form fields and including the Field tag. It exports them as though they do not exist and drops the field description/tooltip.
Frequency: Intermittent and random, with no apparent reason I can find. It happens on some form fields and not on others within the same document. Some documents have no issues at all, others get this error.
Workaround: Ensure there are no "invisible" or "accidental" objects turned into form fields by exploring the Layers panel in InDesign and the Fields panel in Acrobat. Delete any accidental fields in InDesign and re-export. If the issue is still present, completely delete the field and rebuild it in InDesign. Re-export. Delete and rebuild again until the issue is fixed.