F5 BIG-IP : SSL::disable serverside drops X-Forwarded-Proto ?

F5 BIG-IP Virtual Edition v11.4.1 (Build 635.0) LTM on ESXi

My site has a VIP that handles SSL traffic ( port 443 )

The corresponding virtual-server is assigned an HTTP profile that inserts

X-Forwarded-Proto:https

To this virtual-server I recently added an iRule that in the

HTTP_REQUEST

event conditionally disables SSL via

SSL::disable serverside

Is it possible that disabling SSL server-side causes F5 to drop the

X-Forwarded-Proto

header ? or change its value from

https

to

http

?

I ask because I'm seeing traffic arrive at destination web-server missing the

X-Forwarded-Proto

header.