Workaround:
- In the Safari app on your Mac, click Safari > Preferences, and click Websites.
- In the General sidebar on the left, select Auto-Play.
- To enable auto-play for XD, click Allow All Auto-Play from the pop-up menu next to xd.adobe.com.
Alternatively, if you are already in XD, click Safari > Settings for this website. In the pop-up menu, click Auto-Play > Allow All Auto-Play.