@Roastclock I looked up the specs on that modem and it is just a modem, not a gateway. You need one DECO as router just like you set up: your "main DECO" -> switch -> two DECOs both connected...

@MRPHIL3 I think per regulations/rules 6 GHz is designated for indoor use only, that's why they don't make an outdoor rated broadcaster, unfortunately. I like the idea of an outdoor rated unit but...

@Ethan98 If you connect a computer directly to the modem what speeds do you get?

I despise VLANs because that seems to be their function, to segregate/isolate networks. I'm afraid if you need access to a printer it should be on the main network, as well as all devices that need...

The 3 pack that TP-Link sells is supposed to cover 7500 sq ft. Maybe you have too many set up, or one very big house?

@Ledvedder Do you have both WiFis on at the same time? Should probably turn off the other one when testing.