USB ethernet interface misbehaving since 6.6.30

[grant123]

I use a USB ethernet interface which worked fine up until about kernel 6.6.30. Since then, after rebooting it sometimes comes up fine and sometimes does not. If it isn't going to work, the LED on the switch it is connected to illuminates for about 10 seconds during boot and then goes out. Everything appears normal in dmesg and ifconfig even after it stops working. If I unplug/replug the USB interface then the switch LED illuminates for 10 seconds and then goes out again and it does not work. However if I restart the network interface from the command line during those 10 seconds then the LED does not go out and the interface works. I've tried replacing the USB ethernet interface with a new one but the behavior is the same.

I suspected USB autosuspend so I added usbcore.autosuspend=-1 to the kernel command line but the behavior is the same. Any idea what could be causing this? Any other power management stuff I should try disabling from the kernel command line?

I could try changing the kernel config but these days I'm using gentoo-kernel which configures itself. Is it possible to change the kernel config with gentoo-kernel?

[grant123]

I tried a different brand of USB adapter and things seem to be working consistently.

[grant123]

The working one is USB 2.0 and the one that stopped working is USB 3.0 so could be a 3.0 regression.

[grant123]

That's not it. I have another brand of USB 3.0 adapter that works fine.