I have a wifi router that is cabled to a 4-port switch ... off the switch I have a second wifi access point.  I can access the internet with no problems using either the A network (wifi router) or the B network (access point).

I've also been using the A network for 'casting' to my TV using Chromecast unit.  However, because the B network's access point has a stronger signal (and I've fitted a higher dB antenna) I'd like to run Chromecast through it instead of the A network router.

Setting the Chromecast unit up for the B network went fine and connected to the network correctly.  HOWEVER, when trying to 'cast' the unit fails ... the on-screen message says 'unable to connect to the internet', and the error message in Chrome just says it has experienced a problem.

Since random laptops and other devices connect to the internet using the B network (in fact both networks) with no problems at all, I wonder why the Chromecast unit is playing up this way?

Any ideas folks?

R.