I have searched around and somewhat similar issue but not exact same
Ubuntu 18.04 & NC 13 & Nginx
Google WiFi ports forwarded and dedicated IP.
I’m having the issue where NC times out when logging in.
It only occurs in my home network.
It takes so long to login it times out.
The issue occurs with NC sync client LAN, the android APP-on WiFi and from android browser on WiFi.outside my home its flawless.
Even though Google WiFi forces the ip of the server I’m wondering if I should also change NC/Ubuntu to static ip? Currently it’s default-dynamic.