SSL with Apache reverse proxy

Thanks
enabled CF for the domain . DNS proxied
Edge Certificate set to Full ( Strict )
Alway use HTTPS is on …
site now in too many redirect …
I know for whatever reason , i get this mixed content … even though all the content are relative to the root and not hard coded with http … i have used CSP to fix this … it was only happening to single JS file.
I am not developer , i am using pre made web app , is in ASP .NET that requires apache reverse proxy to talk to upstream server ( kestrel ) … as i have mentioned that before , without CF site works …Ssl works and no issues , but just turning DNS proxy on , i get that error .