Hi Marian,

The obstacle of using NLB is

Please note that if you use the TLS termination feature of the NLB, gRPC will break because the NLB does not support Application Layer Protocol Negotiation (ALPN) which is required to convert the HTTPS connection directly to HTTP/2 required for gRPC.

As far as I know, none of CLB/ALB/NLB has supported gRPC owing to different reasons.