ASUS motherboard Intel-i226-V network connection issues

[vortex1]

My connection was randomly dropping in online gaming sessions. I had previously disabled in Network Adaptors, the 'allow this computer to turn off this device to save power..' setting - but it persisted to drop my connection.

Anyway -

I wish I had been able to read this before buying my current motherboard (ASUS Z790-E II):

https://www.techpowerup.com/303854/psa-intel-i226-v-2-5gbe-on-raptor-lake-motherboards-has-a-connect...

I have just gone into Device Manager > Network adaptors > Intel Ethernet Controller I226-V > Advanced > Speed & Duplex > selected 2.5 Gbps Full Duplex. I changed it from the default 'Auto Negotiation'.
I have a Netgear RS700, and the ethernet cable from the motherboard is plugged into the 10Gbps LAN port of the router. That seems ok.

The connection appears stable (for now), but the only problem is that at first I had no internet connection after a restart. I clicked on the network troubleshooter for the ethernet connection and it said I had to set the PC to dhcp/dynamic IP when I previously had it set to static (which is what I actually prefer because my router settings are geared up for that).

So what I'm asking is - how do I keep this 2.5 Gbps ethernet connection but have it set to static IP and not dhcp?

EDIT UPDATE:

I just went into my network settings again, and checked the box for 'Validate settings upon exit' after entering the static IP settings. I have internet - so this appeared to have worked.
Only time will tell if this new speed duplex setting will be more stable..