Are you sure, you are on a rockPRO64? My uname gives me the rockpro64, differs from your rock64! I’m on testing.
root@rockpro tmp]# uname -a
Linux rockpro 6.7.9-1-MANJARO-ARM #1 SMP PREEMPT Sat Mar 9 21:00:40 UTC 2024 aarch64 GNU/Linux
Funny thing, I tried this years ago, found an old thread. Couldn’t remember this, because most of the time I’m on my Pinebook Pro. That was the thread:
https://forum.manjaro.org/t/looking-for-help-with-rockpro64/30966
If you scroll down a bit, you find the conversation regarding the slow ethernet. The solution then was to use the armbian device tree. I don’t want to go that route right now, because currently hdmi is broken there. I guess it is not save just to replace the ethernet paragraph. Or is it?