Acrobat pro accessibility reports Alt text missing, no matter how I enter it into InDesign document

Hi There,

I've tried the following methods to define Alt text for my images, tables etc. and none of them results into a positive report in Acrobat Pro accessibility check:

1- Add Alt text attribute from structure panel

2- Using Object export options (both by Manually entering and by feeding it using XMP)

No matter what, I always get the missing alt text error in Acrobat. (While the Alt text is visible on mouse hover)

Of course I can do it in Acrobat but it's counter-productive since by each new expert, the tags are overwritten with null and have to be re-entered in Acrobat.

Please let me know how is the best way to do this?

Thanks,
Kasra