Multiple Interfaces on same subnet breaks PTP

I have a PC (“main PC”) with two interfaces mgbe0 and mgbe1. Both of these interfaces connect to another PCs A and B (mgbe0->”A”, mbge1->”B”). Both PCs A and B are on subnet 2: 192.168.2.xxx, and I cannot change this. So to connect to the other PCs, I need both interfaces on the main PC to be on subnet 2. After googling I found that I need a bridge to set both interfaces to the same IP address. This is my netplan config:

network:
  version: 2
  renderer: NetworkManager
  ethernets:
    mgbe0:
      dhcp4: no
    mgbe1:
      dhcp4: no
  bridges:
    br0:
      dhcp4: no
      addresses:
        - 192.168.2.86/24
      interfaces:
        - mgbe0
        - mgbe1

With this configuration, the main PC can ping and ssh into both other PCs, and both PC A and PC B can ping/ssh into the main PC.

But a problem occurs: PC A (connected to mbge0) is synchronized with PTP (precision time protocol) to the mgbe0 clock. But when I have the bridge set, the PTP doesn’t work. This is probably because the complete path delay measurement, that is a delay request and a delay response, doesn’t finish.

How can I configure the bridge to allow these requests to work? Or is it possible to have mgbe0 and mgbe1 on different IP addresses on the same subnet? If so, how can i do this?

Thank you for your help!