Hi ,
I have a OWA server configured for SharePoint 2013. After configuration I am able to view the document fine from the browser which redirects to "https://" , but when I click on the ellipsis (...) to get the preview of the document , it shows document URL starting with "http://".
All the sites are default http in SharePoint server. SSL Off loading is done at F5 Load Balance level.
The SPWOPIZone is set to external-https.
Regards