A month ago I bought a triple set of Deco PX50 to extend poor coverage of wifi on a three floor building.

Existing DSL modem (Orange Funbox 2.0/Sagemcom) worked well but it's wifi allowed only to cover 2 floors.

It wasn't a smooth deployment. At first we ran PX50 as router connected to original router. The result - we could use the network in the whole building from phones and apple notebooks, but windows 11 laptops didn't work well. Sometimes they did, sometimes didn't. The problems we observed was related to DHCP. Sometimes DHCP wasn't initialized properly on windows 11.

So, if there was a problem with DHCP, we thought we could actually run it as AP. In such case we would use DHCP from the original DSL router. And guess what? It even got worse - Decos started to interfere with the DSL router and windows 11 didn't worked well no matter if we connected it to Deco wifi, or DSL routers wifi.

The DSL wifi router is IPv6 capable, and due to the limits on IP addressing most providers (also Polish Orange) push to use IPv6 where it is possible. When we connect any deco to DSL router's ethernet port, any windows 11 laptop get only IPv6 addressing, not IPv4 addressing. The result is that you can only access IPv6 capable websites (like google), but many websites being IPv4 only is not accessible. This problem manifests we only observer on windows 11 laptops. Once connected to the network infected by decos we noticed that these laptops tried to refetch their IPv4 each several seconds but without any success.

And we came to this observation after more then two weeks of testing. We even insisted on Orange that it could be that Funbox DSL router that was defective, they changed it to a new one. We went through various AP/Router combinations. Tried all combinations of roaming, beanforming, switching Smart DHCP off and on (switching it off doesn't help).

So - right now we can get to the internet on windows 11 laptop only when not using decos. And it works best if these are not powered.

Is there anything we can do, or we should just return it?