Istio TLS origination with IIS external service. How to disable HTTP/2?

[jesse]

Looks like the same issue here:

Cannot reach external service with TLS (using or not an egress gateway)

One more step: the example here now works. I had an old destination rule that was overlapping with others I was installing… Unfortunately, things start to do not work anymore when I try to do the TLS origination in the gateway, following the guide here. When I curl from the sleep pod (my client) to my external service I always get a 503 UC as a reply. Also, I’m trying to understand what each component is supposed to do in the tutorial. Can anybody please explain what this destination rule is…

And I just encountered it with an Adobe endpoint on the web too, also SOAP.
So, apparently any SOAP / IIS endpoint hates the envoy TLS origination. Any ideas would be great!