Origin request header null

When we make ajax POST call from Safari browser Origin request header is set to NULL. This issue happens on IOS14 only, on IOS 13 Origin header is set correctly. We make these ajax calls from inside an iframe. This is legacy application so we cant change implementation from Iframe. AJAX calls coming from same domain are treated as calls coming from different domains in an iframe on Safari browser for IOS 14. Does anyone know what security policy changes were made to IOS 14 that is misrepresenting calls to be coming from different domains and how this issue can be resolved?