Recently I created some UI documentation that had several Masked images on the page, and these looked great in an Exported PDF document, but when uploaded and viewed on a Confluence website the masked where missing and images positions where moved to where the mask was. but when the same PDF was downloaded from Confluence to the desktop the masked came back.
My workflow was to export XD Artboards as PDFs; import them into Indesign and Export the entire document as PDF. my workaround was to replace all PDF with PNG files.
Not a difficult one to solve but if working with Jira or Confluence be aware mask dont work correctly.