Dashboard performance over internet

Greetings,

Local Grafana server
postgres database
the dashboard has gauges and charts


the server is connected to internet.
i have configure the router and port forwarding to connect using public ip.

my laptop is connected to the internet on the same network with the server

#using my laptop, connecting to the server using the public ip:port
works fine, loads all the dashboard fast.

#using another network internet,
the dashboard loads fast, gauges loads fast
but the charts takes long time to load “forever”

i have tried to make 2 dashboards, one for gauges only, one for charts only, still same issue

any idea to improve the chart loading performance over internet