Disappointing asrock g10 with OpenWrt (last 22.03)

Great speed.

With an old MiWfi-D2 STA/AP repeater & Padavan

We don't really know you open wrt configuration.
Network,. wireless etc

Confiuration:

As I described at the beginning

It has been pointed out that relayd involves exporting packets from kernel space to process them in user space, which has a significant performance penalty. "Repeating" the LAN of an upstream network that only offers a regular wifi AP is done better with a direct routed client and symmetric routing instead of relayd.

Also is your speedtest machine connected to the same radio as the uplink, the other radio, or Ethernet?

Everything is the same

If I change router it stays in the same place next to me

I don't change WIFI Master either, which is an Orange LiveBox 6

May be in direct sta / lan it would be better but it doesn't work with my box
This only works in WDS OpenWrt-1 < -- > WDS OpenWrt-2

All the tests are : Computer LAN GHz < -- > OpenWrt or Other < -- WIFI 5 GHz --> LiveBox 6
There is still the same connection in WIFI 5 GHz
Internet = fiber 2 * 1Ghz , i use always the 2.5 GHz lan port

All of these issues have never been fixed since at least version 18.xxx

If you haven't investigated CPU performance tuning this reply in another thread may be helpful. While specifically directed to the ipq8065 based R7800, the information (except exact CPU frequencies) also applies to ipq8064 based devices such as your G10.