Dear friend!
The functions you need may or may not be realized at one time.
It is recommended that you allocate another VLAN to the device on the OLT side, open the WAN setting window on the local web page, and create the VLAN allocated by the OLT. Then, set the 802.1p priority to the 7th level (highest level). Then, bind the SSID to port SSID2. Your phone only needs to connect to the wireless network of SSID2.

Thank you!