Thx for yr reply, Victor.
I think both the switch & the specific port are functioning. I plugged in a laptop as suggested. It got an IP from VLAN1 if I configured the port on VLAN1, got IP from VLAN2 if configured as VLAN2. Internet connection works perfectly.
The AP ssid is on VLAN1, if switch port on VLAN1 it does not work, but if on VLAN2, it works!!
Then if both AP & port on VLAN2, it does not work either.
Really can't explain!!