The r8125 plug-in was added to the 21.02 version. It was selected during compilation. However, after installation, it was found that the 8125b network card could only work at 1000M, and could not negotiate to 2500M. Manual modification would not work! How can I solve it?
The reason why mwan3 does not work properly is that it uses iptables, which cannot be fully adapted to the nftables in 22.03, unless mwan3 uses nftables!
Still test 22.03, even if you don't want to use it long term, just to check/ confirm if it's working in the newer kernel. Once you know the answer to that, you can either:
backport the r8152 kernel changes between v5.4 and v5.10 fixing this
or use fw3/ iptables instead of fw4/ nftables on 22.03
Neither will be particularly fun, but one of those options is the only possible way.
After upgrading the 22.03 system, 1G is also automatically negotiated, and 2.5G is successfully negotiated after passing the command you gave. What is the reason for this?