Disabling htx for h2

[phaze-debug]

We are trying to enable h2 communication via marathon lb (running with HA Proxy 2.0.10) and want to disable HTX as we suspect it might be causing some issues that we haven't been able to track down yet. The HA Proxy documentation says HTX can be disabled by setting no option http-use-htx either in the default/frontend/backend sections. We tried all 3 but setting in default section causes marathon-lb to fail during start up. Setting in either front end or backend sections also fails (not sure what the failure is yet but the specific process doesn't come up). This is how we have been trying to set in the backend. Would appreaciate some guidance on how to set no option http-use-htx -

"HAPROXY_1_FRONTEND_HEAD": "\nfrontend {backend}\n bind {bindAddr}:{servicePort}{sslCert}{bindOptions}\n mode {mode}\n",
"HAPROXY_1_PORT": "xxxxx",
"HAPROXY_1_BACKEND_SERVER_OPTIONS": "  server {serverName} {host_ipv4}:{port}{cookieOptions} proto h2\n",
"HAPROXY_1_MODE": "http",
"HAPROXY_1_BIND_OPTIONS": "proto h2",
"HAPROXY_1_GROUP": "trusted",
"HAPROXY_1_BACKEND_HTTP_OPTIONS": "  no option http-use-htx\n"