I would like to ask for your help here.
In my home network there are two openwrt routers with the following configuration/topology:
Router 1, main router:
Connected to the ONT via cable
2.4GHz: Access Point of the home devices
2.4GHz: Access Point of the guest devices
5GHz: WDS Access Point of the WDS Client (Router 2)
This router just works fine, no performance issues
Router 2, WDS client (followed this guide):
2.4 GHz: turned off
5 GHz: WDS client as described in the guide
Desktop PC with no WLAN capabilities connected with cable to Router 2 running Windows 10.
There are two thick walls between Router 1 and 2.
Originally the Desktop PC was connected with cable to Router 1 and worked seamlessly.
The whole purpose of the above setup is to provide internet to the Desktop PC since cable connection is not possible anymore and it does not have WLAN interface.
This setup works:
From the desktop PC I can ping Router 2 and round trip time is less than 1ms
From the desktop PC I can ping Router 1 and round trip time is less than 10ms
I can browse the internet, watch youtube form the desktop PC without any issues.
Under heavy load when I ping Router 1 from the desktop PC round trip time varies between 10 and 2000ms and there are packet losses sometimes (maybe this is normal under heavy load).
Also, the download speed is very inconsistent. It spikes up to 40-60 Mbps then slowly (under 5-10 seconds) falls down to almost zero, than spikes up again and falls again repeatedly.
When I watch the traffic graph in LuCi during downloading a large amount of data I see that there are 5-10 second intervals when traffic is normal (~60-80 Mibit/s) and there are 5-10 second intervals when there is no traffic following each other. It seems that the issue is only present under heavy load.
I tried different channels and channel width combinations but got inconsistent results.
Do you have any idea what could cause this issue?