Problems with I219-V (on NUC6i3SYK) at 1 Gbps

Hello.

I have a NUC6i3SYK which has I219-V NIC on board.

First of all, there are no problems with network connection when the card is connected to 100Mbps capable switch/router.

But there are problems when it is connected to 1 Gbps capable router. After switching NUC on, and booting into Windows, after some time (1-10 minutes) the connection quality decreases really bad, ping to the router raises to 500-1000 ms and some packets get lost.

Disabling/enabling the card fixes it for another 1-10 minutes.

Setting Link Speed to 100Mbps also fixes the problem.

I ruled out the router as the cause, because another PC connected to the same router works flawlessly on 1 Gbps - it also has I219-V but on another motherboard (ASUS Z270G).

Of course I tried switching router ports and cables between the two PCs but it didn't help.

Driver version: 12.17.8.9 (Intel PROSet version: 23.1.100.0)