are the buttons there if you export your document to PDF Print with export preset [Smallest File Size] ?
If not, that is the answer, why.
Best make a feature request at InDesign UserVoice:
If done please come back here and post the link to your request so that others can vote for it.
( ACP )
Share for review creates a flat, small pdf version to view online for those you share it with. So no interactivity of any kind is present.
Same bug, would like a fix in the next update. Defeats the purpose to share for review when elements are missing. 😉
Not a bug, as designed.
A pretty daft design, Frans...
"hey guys, you can create interactive pdfs with url linked buttons - to impress your clients"
"hey guys, we've created a process to streamline your proofing to impress your clients"
"hey guys, we've 'designed it' so that both elements of OUR OWN PRODUCT are incompatible, we're not too bothered about impressing you or your clients"