Slow uploads on an i218/i219 NIC? It’s potentially a driver issue and here’s the fix:
ethtool -K enp0s31f6 tso off gso off
You can confirm the change immediately using netdata or similar as upload will jump from 500Mbit ish to 900+. This will need to be run after each reboot, so if it works for you, may want to add it to crontab etc.