Hi @Destauneu27
This is because the IB2 still tries to act as a router for the guest network, and therefore “eats” the packets instead of sending them to the IB3.
You also might experience some DHCP conflicts in the guest network when using this setup.
As there is no way to configure this, this is unfortunately an “unfixable” issue. The only way to make it work is to use other access points, i.E. a WLAN Box 2 or 3 instead of the IB2.
Best,
r00t