Guest WIFI on second router not working

Hello,
I have router1 (without using wifi) connected LAN to LAN to router2.
On router2 I use wifi (for my home network) and it works fine.
Now I created a virtual wifi for guests, but the clients can't access the internet.

Router1:
IP br0: 192.168.1.1

Router2:
IP br0: 192.168.1.99
IP br1: 192.168.2.1

The clients which are connected to the guest wifi can ping 192.168.2.1 but not 192.168.1.99 and also not 192.168.1.1 (which is the internet gateway).

How can I allow guests virtual wireless...

Guest WIFI on second router not working