@sectarian Well I did find a Deco X50-Outdoor model that may work if you can run a wire into the shed, (supports PoE): https://www.tp-link.com/us/deco-mesh-wifi/product-family/deco-x50-outdoor/

As I understand after setting up mine 1 1/2 month ago all three LEDs 2.4, 5, and 6 on the RE815XE should be ON, meaning you should try to connect each band to the like band on the router. That said...

I don’t know of any external antennae options I’m afraid. Any windows facing the shed/windows on the shed? Windowsills are great places to put a WiFi product, (I use Velcro to secure them), to help...

@tr6pilot If OFDMA/802.11ax MU-MIMO is enabled on the Deco unit try disabling it. You are connecting a WiFi 5 (ac) extender to a WiFi 6(E) product...

@dbsoccer Well there are a couple of things that would improve: 1. Throughput is higher 3000 Mbps vs 2300 Mbps, meaning less likely you'll get complaints of slow internet, more devices can be...

@dbsoccer Since you've wired the house, (smart idea by the way,) the simplest way to fill the dead spots is to add Access Points to the rooms where there's a dead spot, and connect them via ethernet...