Openwrt wireless repeater

Hello,

I have Unifi lr ap but my coverage in the room is very low. So i thought why flash my xiaomi mi router 3 with the openwrt software and put it as a wireless repeater between my unifi ap and my room. I tried to follow these steps precisely: https://openwrt.org/docs/guide-user/network/wifi/relay_configuration

But after following these steps the client connects to my unifi ap sometimes and i get an ip error on my phone when trying to connect to the repeater.

Can someone please help me?

Thanks in advance.