I tried to change the connectTimeout from the default 1000ms to a larger value by changing the configMap value, but this has no effect.

#kubectl get configmap istio -n istio-system -oyaml | grep connect
# Edit this list to avoid using mTLS to connect to these services.
# TCP connection timeout between Envoy & the application, and between Envoys.
connectTimeout: 10s

This is what Pilot generates in CDS, connectTimeout is still 1000ms
clusters": [
{
"name": "in.8079",
"connect_timeout_ms": 1000,
"type": "static",
"lb_type": "round_robin",
"hosts": [
{
"url": "tcp://127.0.0.1:8079"
}
],
"features": "http2"
},
{
"name": "in.8080",
"connect_timeout_ms": 1000,
"type": "static",
"lb_type": "round_robin",
"hosts": [
{
"url": "tcp://127.0.0.1:8080"
}
]
},