I recently encountered a similar problem … I reinstalled my laptop and my Realtek 8153-based USB LAN adapter (classically 1 Gbps) behaved exactly the same way.
After a bit of research, I found an adjustment in my original system (which I had already forgotten 
) - namely to blacklist the respective adapter from the TLP.
It was enough to create a file /etc/tlp.d/54-blacklist-usbeth.conf with the following content
USB_BLACKLIST=“0bda:8153”
and since then carrier is stable again.
Maybe this will help you too (of course you need change the USB id to your adapter).
EDIT: Just for the record - the source of the solution is https://askubuntu.com/questions/1044127/usb-ethernet-adapter-realtek-r8153-keeps-disconnecting