Minecraft - Connection Lost - Timed out Connecting to Minecraft Server

[fmalloy]

New RBR20. Connecting to a friend's Minecraft server, initially connects to the server, and the game starts ok as normal. About 5 seconds later - "Connection Lost" and "Timed Out". Computer is connected to the RBR20 by Ethernet cable, not Wi-Fi.

Exact same computer and setup, swap out the RBR20 for the old Nighthawk R7000 in 2 minutes, and the game stays connected. Friend's Minecraft server working fine, others connect ok. The problem is the Orbi.

I'm comparing the Orbi router settings and the R7000, and they look the same. I have no special blocking turned on, no Parental Controls. The settings look identical except in the R7000 QoS is turned OFF but it is ON in the RBR20. I am going to try that when my kid finally gets off. 

Until I try this - could it be QoS causing this disconnect?

[FURRYe38]

What Firmware version is currently loaded?
What is the Mfr and model# of the Internet Service Providers modem/ONT the NG router is connected too?

Is Armor or Circle enabled? 

[fmalloy]

I have the latest firmware.

I don't know the internet provider's modem (it's a small Internet provider using Wi-Fi microwave dish on the roof and the modem is  in the attic) nor do I know why this matters. My internet has been rock solid.

I do not have Armor or Circle enabled.

[Mikey94025]

If Minecraft requires port forwarding, then swapping out your router will change things like the computer's LAN IP address.  Port forwarding rules must be setup on the Orbi like they were on the R7000.  Or perhaps you're relying upon UPnP to set these rules up for you automatically.  Note the IP address of the computer and ensure that the port forwarding rules are correct for the outside port and the internal computer IP.

Another problem may be that your Windows host is treating the new wireless network as Private whereas your old wireless network was set to Public.  Even though you named the wireless SSID the same it will be a different Windows network (connection).  If Private, then the port will be blocked by the Windows firewall.

In short, setup port forwarding again and use tools like https://canyouseeme.org/ to verify that the port is visible on your computer to the outside network.