So they never released a proper working BIOS for 11th gen? That is odd. Modern EVGA moment I guess.
AX201 does not work, but you should be able to replace with DW1560 or DW1820A and that works on even XP. Similar or better than 8265 (last working on 7)
For I225-V, I haven't seen that before, nor do I own a 225-V based board. I know some of the earlier chips can be funky with weird issues. Not entirely sure if fixable. Maybe see if SDIO has a better driver? Also I fixed the link.
Probably not the solution you came here for, but I suggest disabling internal Ethernet entirely and just using a Solarflare/Solarstorm SFN 10G Ethernet card.
https://www.ebay.com/itm/126165782346
I'm using a SFN5161T myself. I think the SFN5121T and SFN5161T are mostly the same card. I've tested mine and the card works in even XP too. Although the drivers are a bit rare, going to try to find them again and add to 7 post. The card is 10G, which is an upgrade over 2.5G 225-V, and works fine in a downgraded chipset slot. You can use this in the bottom x16 (electrically x4) and it should just work.