Have you still got the old Sky Router ?
If so what happens if you use the Sky Router instead of the NowTV Hub router (which are clones of the Sky routers).
Did you have Sky Sheild setup when on Sky, if so maybe go back into your old Sky account and switch off Sky Shield to see if that makes any difference.
Also maybe pop over to the Sky Broadband & Sky Q Forum to see if anybody else had similar issues to what you are encountering.
Should you ever encounter poor internet speeds or an outage on your internet line, then before contacting nowtv you would need to plug in the NowTV Hub router to allow them to check your line.
Did you jump over to the Sky Q and Sky Broadband Forums to see if anybody over there posted a solution of your problem with the Sky Q box not accepting the WiFi password of a third party router ?
Going forward should you wish to use the NowTV Hub router instead of your old Sky Router, then perhaps contact both the NowTV Broadband Team and also the Sky Q Support Team for assistance & help.
We’ve just moved to NowTV broadband and have this issue too. Have managed to connect all our devices to the new broadband but when trying to connect the SkyQ box it is t recognising the password - which I have definitely put in correctly.
Has anyone managed to resolve this is this is I have tried resetting the router and that hasn’t worked so currently we are without catch up etc??
If anyone else does have this issue like my mother in law did, make sure you click connect to a Sky router/broadband , then long press the WPS button (two arrows in a circle on front of the router) , Sky Q box will then find it. @Sue165002