CW-TWL-SFP+ (N150): i226-V link flapping on both igc ports – is there a newer BIOS than TW

Hello,

I'm running OPNsense (FreeBSD-based) on a CW-TWL-SFP+ box and I'm experiencing severe link stability problems on both Intel i226-V ports.

Hardware / BIOS info:

Product Name: CW-TWL-SFP+

BIOS Name: TWL-T7BIOS 

Build Date: 06/13/2025 (Project Version ADN V1.1, AMI Aptio 2.22.1293)

CPU: Intel N150 (Twin Lake), 16 GB DDR5NICs: 2x Intel i226-V (igc), 2x Intel 82599SE SFP+ (ix)

Problem:

Both i226-V ports show constant link flapping (link up/down every few seconds). This causes heavy packet loss (~68%) and eventually no usable connection at all. The problem occurs with different link partners (2.5G switch, FTTH modem, and a direct connection to a MacBook with a 2.5GbE USB adapter) with different cables with auto-negotiation as well as with fixed media settings (1000baseT full-duplex / 2500Base-T)

What I already tried:

ASPM is disabled in BIOS, EEE disabled via sysctl (dev.igc.X.eee_control=0), Fixed speed/duplex instead of auto-negotiation, Different cables and link partners

Since this looks like the well-known i226-V stability issue that Intel addressed with newer firmware/microcode, my questions are:

Is there a BIOS version for the CW-TWL-SFP+ newer than TWL-T7 from 06/13/2025 that includes updated i226-V firmware or related fixes?If yes, could you provide a download link? pan.changwang.com currently returns a 403 storage error ("AccountProblem") for all folders, so I cannot download anything there. If no newer BIOS exists: is this a known hardware issue with this board, and what would you recommend?

Thank you very much!