Today I faced a problem with my network: my wifi router running Openwrt was losing connection, and the only way to recover was a reboot. Then it would work fine for some minutes, until the logs started showing errors like these:

mtk_soc_eth 1e100000.ethernet eth0: NETDEV WATCHDOG: CPU: 3: transmit queue 5 timed out

I found a git issue mentioning this problem, where it was recommended to disable offloading using ethtool:

ethtool -K eth0 tso off gso off gro off

That didn’t fix the problem. I also have a Dell monitor with integrated usb-c hub/ethernet/displayport I use as a docking for the work laptop, and noticed the ethernet port it is connected to was showing a lot of activity despite not being currently connected to a PC. Only a power cycle of the monitor (physically disconnect power, since the “power switch” only affected the screen) fixed the problem. Apparently when disconnected from a PC these type of hubs can flood the network with network packets (pause frames).