@phil_rv Really getting a bit annoyed now... Simplest operation - plugging a NAS into an unused port and same issue as before - its as if the port is blocked... packets not getting through but...

@Andone Yes all working - everything plugged in the same ports. Only difference the factory reset.

@remz Seems very similar to the issue I had on the same switch https://community.tp-link.com/en/business/forum/topic/205818

@Andone Thanks I agree that the blocking is unlikely to have been the issue. All I know is that without a change of anything physical (cables, devices, port number) that a factory reset cured the...

@Andone thank you - interesting to know that the LEDs are the only way to see blocking status. I think my question should really have been not just if blocking a port would show the same symptoms as...

So after checking all settings (everything was on defaults anyway) - I've done a factory reset and all is working again! So not sure why? Would the loop protection block do this? If so - is there a...