Connection issue with multiple Listeners that are using the same Hybrid Connection

[GitGraf]

I want to setup remote access to a some devices running a REST interface with azbridge. To keep my footprint small, I would like to use a single hybrid-connection for my 2 devices, using the "Logical Port Name" to choose which device I want to connect to. I noticed that requests to my REST backend start to sporadically fail when I have more than one Listener running concurrently.

Remote Forward on PC-1:
azbridge -T "hybrid-conn-1:PC_1-http/localhost:9000" -x "<Connection String>"

Remote Forward on PC-2:
azbridge -T "hybrid-conn-1:PC_2-http/localhost:9000" -x "<Connection String>"

And on my local machine:
azbridge -L "localhost:9000/PC_1-http:hybrid-conn-1" -x "<Connection String>"

If I then query localhost:9000 repeatedly, I sometimes get "curl: (52) Empty reply from server". I tried this with other protocol-types (e.g. ssh, rdp) too, and it behaves similarly.

user@user-kubuntu:~/work$ curl localhost:9000/status/running
curl: (52) Empty reply from server
user@user-kubuntu:~/work$ curl localhost:9000/status/running
true
user@user-kubuntu:~/work$ curl localhost:9000/status/running
true
user@user-kubuntu:~/work$ curl localhost:9000/status/running
curl: (52) Empty reply from server
user@user-kubuntu:~/work$ curl localhost:9000/status/running
curl: (52) Empty reply from server
user@user-kubuntu:~/work$ curl localhost:9000/status/running
true
user@user-kubuntu:~/work$ curl localhost:9000/status/running
curl: (52) Empty reply from server

When I stop the Listener on PC_2 and repeat the test, I get the correct response every time. Some documentation from Azure (https://learn.microsoft.com/en-us/azure/azure-relay/relay-faq#quotas) states that up to 25 Listeners may be connected to a Relay concurrently, but I start seeing issues when just 2 are connected.

To be honest, I am not sure if the root cause of this is with Azure Relay itself, or something specific to azbridge, or maybe a mis-understanding of the docs on my end. Would be great if somebody can confirm!