Error JSON decode failed (v2.6.3)
Hi. I have installed xmrig-proxy 2.6.3 and I am doing configuration tests. 
I have searched the repository and there are other problems that give this error, but they do not apply to version 2.6.3.

It works correctly if I use a port xxxx, but if I put port 80 on the side of the miner it gives me this error: 

[mydomain.com:80] JSON decode failed
[mydomain.com:80] JSON decode failed
[mydomain.com:80] JSON decode failed
...

It is a server-side problem (xmrig-proxy), because if I connect the miner directly to the pool through port 80 it works correctly.

It is important since some miners are blocked by the firewall, but this does not happen through port 80.

Thanks for your attention