If you change the p-bit on a device level and click apply, changes are not taken over. I have tried the config with P3.95 on EDM2003B.
It seems a VIF issue. When creating 2 devices with the same MAC address and the same Vlan id.
1. Only change the Vlan priority on first device, apply and start device, from capture, you can see two device still use old Vlan priority.
2. Change the Vlan priority on first device then click apply, then change Vlan priority on second device, then start device and capture packet ... the two devices still use old Vlan priority.
3. Change the Vlan priority on both device and then click apply, start device and capture packets, only in this case, the change take effect.