@b00rdly Thinking about that from the other angle. You may wish to contact iRobot Support with that issue. I've been on Deco forum for about a year, can't recall anyone raising an issue with Roomba...

@b00rdly Does not look like ports issue. Have you enabled UPNP in Deco as recommended by @ImtiazAli ? Other than that, if you have Main Deco connected to ISP router, it would make sense to test...

@b00rdly I have found for you a useful guide in how to find if outbound ports are blocked. That should be the first step in troubleshooting. See this link:...

@ImtiazAli From what I read in Roomba FAQ, they need outbound ports opened on firewall. The document you shared is for opening inbound ports on Deco router firewall.

@Anthonyb22 In regard to Access Point vs. Router mode, here is formal TP-Link document: What’s the difference between Access Point mode and Router mode on the Deco? Informally speaking, Access Point...

@Anthonyb22 Results of speed test are dependent on geographical and networking location of speed test servers. It is possible that when you don't use VPN, for some reason an app chooses server too...