Having issues with Chromecasts on my network - it's been getting worse recently (something updated perhaps?),  When trying to connect to the chromecast to cast from Youtube (or just about anything), the two chromecasts (two different rooms) often, but not always, cannot be seen.  They are on the network and work when manually controlled by remote, they work when a tv code is used, but cannot be seen directly for casting.  

Our network setup is our modem connected to our AX72 / AX5400 V1 (Depending on where in the settings you look it has different names).  The router then has a couple of lan connections: one to a PS5 and one to our powerline setup.  The powerline (can't remember all the models, but a pair of WPA8631P and a pair of wired only devices for work PCs) gives a wired way to extend our WiFi to our office and extension, and is all setup using OneMesh.  We are using Smart Connect to have the dual bands 2.4 and 5Gz act as a single network.  As part of this issue I have also gone and updated all the firmwares for the extenders - without any improvement

Firmware Version:

1.2.6 Build 20240619 rel.72016(4555)

Hardware Version:

Archer AX72 v1.0

While it's hard to pin down exactly what the issue is, I have a strong suspicion that the issue occurs when either:

• The Chromecast is on a different band to the device we are trying to connect from
• The Chromecast is on a different access point (the router or the powerline extenders) to the device we are trying to connect from 

The second case I can definitely confirm is the case this evening - made worse by the fact that OneMesh has a habit of not changing to the strongest signal if the old signal is still available - my phone is still connected to the distant upstairs extended dispite being 2m from the main router (and, incidentally, the Chromecast I want to connect to).  

The issue has been present on 4 different Chromecasts of 3 different hardware versions, on 4 phones and 3 tablets covering 5 different manufacturers and probably 4 android versions - and about 7 different apps trying to cast.  

I understand there are meant to be settings related to AP isolation, however,  I cannot find such a setting in either the router admin console or via the tether app.  Actually I've seen many complaints of similar types all with the simliar issue that the router is not exposing the chromecast across the whole network, and with different terminology on most routers - but not that I can find on my router).  

What is the solution for this version of router and where can it be found in the maze of settings?