Question Connection error from UnityWebRequest to my plesk server on older devices

[Danny325]

Server operating system version

Ubuntu 18.04

Plesk version and microupdate number

Plesk Obsidian v18.0.46

I am developing a game which uses my API hosted on our plesk server.
Everything seem to be working fine for "newer devices", but on ~5 year old devices the server seem to be refusing connections.

Devices with issues:
-Xiaomi mi 4c miui 10.1 (xiaomi.eu android 7)
-Galaxy s6 edge (android 7)

According "pacpdroid" on Mi 4c (network monitor):

https, 443
traffic: 4,6kb recieved - 749 byte sent
Start end of connection: 15:27:38.184 - 15:27:38.413
packages: 6 recieved - 10 sent
payload 4,7 kb

I am using nginx web server and lets encrypt for SSL.
etc/nginx/conf.d/ssl.conf:

ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384$
ssl_prefer_server_ciphers on;
proxy_ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;

There are no logs like there never were a request made from the mentioned devices, not in web logs or nginx logs.

 

[Nik G]

hello @Danny325 ,
you can try to install sslit extension, open it and enable "TLS versions and ciphers by Mozilla"
with choosing maximum compatibility.

by default Plesk uses strong policies, so there can be problems with old OS'es and devices.

did you see any errors in domains web server logs?
did you have web application firewall installed (probably it block older devices by some rules)?