You’re all over here. You have a complex network setup and you can’t use consumer grade equipment (eero and Deco) to do what you want to do. You need two things.

  1. a router / WiFi solution

  2. a PtP (point to point) wireless bridge to connect your two buildings.

By far, the most recommended system on this forum and likely best match is Unifi. Ubiquiti UniFi is a community of wireless access points, switches, routers, controller devices, VoIP phones, and access control products.

There are numerous threads about Unifi installs here and videos online.

I posted a link to a PtP tutorial here as well https://youtu.be/_46QuVNopsM

Also, it’s worth nothing Unifi does have chat and email support, but that’s not meant to design your system. If you need a full design there are many mid-grade/small IT shops that can design for you.

You likely would need a UDM-Pro, multiple WiFi 6 APs or better for the first set of buildings that are hard wired, a PtP bridge (one device on each side, a pair of two total) and then another WiFi 6 AP or better to broadcast WiFi from the bridge at the out building.

Unifi has everything you need.

for a complete system of wifi mesh and p2p wireless bridge i would go with unifi. nice ecosystem.

but seriously for stability and performance the AP need to be hardwired and backhauled

I know this is going to be unpopular, but I have been using Google Wifi Mesh for a few years and it has been superb. I am in a house with two teenagers and they are constantly gaming and streaming video simultaneously often whilst in video chats with their mates.

The wife and I also stream all of our TV, in 4K. I am also running a home server, that runs Jellyfin Media Server and Qbittorrent, a 20 user Minecraft Server, in a Docker container, and Home Assistant in VM.

I must have around 50 IoT devices such as smart switches, bulbs, thermometers and humidity sensors, IR blasters, door sensors, a couple of cameras and 10 Google Home speakers/displays.

I have an Xbox, Nintendo Switch and a Sony PS/2 Slim which is hooked up to a Raspberry Pi 3B+ as a games server. As well as a myriad of phones, tablets, Chromebooks, laptops and desktops. If the kids are having a Minecraft party I could have 5 in the house with another 5 connected via the internet.

I consider myself to be a heavy user, it has been known for there to be up to 100 different devices on my network. The Google Mesh Wifi never drops out, the speeds over the LAN are good and we never get buffering whilst streaming or any real lag when gaming. There have been times when remote players have complained of lag on Minecraft, but nothing major.

I have 4 APs placed in strategic positions around the house, to get the best coverage I can. I have considered upgrading but whilst it continues to perform well I am not going to bother. The wife wants me to get those Minion access points.

I was bought the Google Wifi Mesh as a Christmas gift. TBH it has been a plug and play experience and had no issues to speak of. That said my mate had virtually the same setup and he had no end of trouble with it.

If you have to do mesh, do tri-band with dedicated backhaul channel.

For the most stability, do wired backhaul. But at that point just do an actual system like Omada if you can afford it.

I just learned Ring cameras don‘t work with the managed ubiquiti switches and eco system...

Ring camera are the worst for missing events, I used to have a 50/50 chance at best of it detecting people, However if it’s raining hard in the middle of the night you can be assured it’ll ding a hundred times with ‘Person Detected’.

Hardwired, or deal with the instability

For stability, no question Orbi Pro. The management options are poor, it’s stupidly expensive, the UI is terrible but it’s stable as hell with decent speeds.

I’ve used ASUS, Deco, Eero, Google WiFi, TP-Link Omada and UniFi, all of them had issues somewhere along the line. ASUS was fast but firmware’s were very unstable. Eero was reasonable but still would have occasional wobbles. Google WiFi needed weekly reboots. UniFi meshing was simply awful in comparison.

I finally gave in and ran cable everywhere which was not easy. I’m running UniFi now, but not in mesh, and only because I want a single pane of glass for visibility over my entire network.