Background:
An accessible PDF needs for all graphics and pictures a boundingbox.
This is used by AT e.g. to set a focus to a visual impaired user.
Using the PDF export a boundingbox is defined for all linked images.

Problem:
Often the boundingbox does not fit to the visible area.
AT user get wrong information, in fact the file is not accessible.

Reason:
Only a part of the linked asset is visibily placed in InDesign, the rest is cropped.

Result:
The boundingbox is bigger then the visible area.

Workaround:
You can fix this in Acrobat theoretically, but this is nor real workaround as you only edit values and dont have visual feedback.

Attachement:
InDesign sample files and accessible PDF with boundingbox example + visible error.