Suppress x-forwarded-* headers for egress traffic

Hello,

Envoy proxy uses certain special http headers, such as x-forwarded-proto and x-forwarded-port. Is there any way to suppress these?

Normal VirtualService header manipulation or Lua EnvoyFilters don’t seem to work, as Envoy considers these headers to be special and won’t accept any changes to them.
(https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#x-forwarded-for)
If i remove the headers with a Lua envoyfilter, then the requests fails with a 404 NR.

Do you have any ideas?

Background: An external webservice resource that is being consumed from within my mesh for unknown reason does not accept requests with these headers.I can’t make them fix that issue on their side, so i need to find a way to adjust my requests to their requirements.

Thanks in advance,
Jens