@leatherman 

Unmanaged switches can't carry VLAN tags, if you plug an AP directly in to your VLAN capable switch removing the unmanaged switch - does it work?

How did you rule out the unmanaged switches?

@leatherman Hi, thanks for the response. We had already considered this possibility, but research showed that modern switches should be able to cope. We tested it. If we configure the PVID of the router to, for example, VLAN 10, and connect to the WAP on the same VLAN everything works perfectly, but only for that VLAN.

It is also worth noting that, for well over a year, the setup worked pretty well, but there were only occasional issues connecting (which I put down to a faulty WAP or wiring). However these got worse over time, I think as leases expired, especially whilst we were closed for a long period. The internal network also worked well, we could talk to the server over wireless for example on VLAN 10. Hence I believe the issue is more to do with connecting to the DHCP server.

Thanks

Steve

@Fae Hi, thanks for the update, I will have a look at this and try it out.

@leatherman  To add to to this, we do not have a router with VLAN support. This is where I am falling down and I had already considered this was the problem.