Question Ethernet lost after sleep mode

Satan-IR

Splendid
Ambassador
What is your OS?

See if turning "allow the computer to turn off this device" in power management in through device manager helps.

Or generally turn off any 'sleep' or reduce power options and wake on LAN options in the power management section for the relevant ethernet/network device.

Also, sometimes, it is resolved by reloading/reinstalling the driver for the network adapter/device.