wlan1 Interface running as "slave"

Hello,

For some reason my wifi network is now running in “slave” mode. The impact of these seems to be that wireless devices get IP addresses from my gateway (192.168.1.x) instead of joining the same subnet as my wired devices (192.168.88.x).

I have factory reset my router and installed the latest update, but for some reason this is still happening.

How can I fix this?

Thanks a lot for any help you can offer