Things I've tried so far
Allow an app through firewall for both Main and sub computer (including original MetaTrader 5 tester as well as the stand alone version)
Advanced fire wall: Inbound & Outbound - enable everything, full settings (for both main and sub computer)
What else could I try? Thank you!
I've set up sub PC like this
On my main PC, Agents tab, once the Optimization running all the Core of the main PC running normally. But the Local Network farm status only constantly changing from "connecting" to "ready