PlayBase surround issue, and/or wifi problem

Hi,
I've had my Plabase + 2 Play:1 set up in surround mode for a year + without any issue. Everything on WiFi setup.
The PlayBase has had a wired connection since i got it, but when I got the Play:1s I switched to WiFi as I did not want to add cables to the surrond speakers.

A while ago I noticed that there was no longer any sound from the Play:1s. I tried to remove the surround, and re-add it. But it gives me an error.

It goes through the set-up, I press the buttons on the speakers to add them to the surround.
I get notified this:

"Preparing the speakers in this room to work together. This may take a minute."

I can play anything on the Play:1s on their own, but I can not add them to the PlayBase as surround speakers. It goes through the set, I press the buttons, and comes to:

"Preparing the speakers in this room to work together. This may take a minute."

Then I get:

"Setup problem

There was a problem preparing your speakers.

Please check your network connection or the power on your speakers in this room"

I tried through advanced setting switch the PlayBase to Wifi but when I try to connect it give me an error message:

"Wireless Problem
Please check the name and password for your network. Ensure you are using a 2.4GHz wideless network.." etc..

I know that the password is correct, it works on all other devices, including 4 other Sonos Speakers.

Could this be a faulty Wifi card in the PlayBase that messes thing up?
How do I verify that?

i have tried with a different router, change the SSID, changed the password etc. Everyting else, including the other Sonos speakers will connect, but not the PlayBase.

Thanks!