Wi-Fi broken by firmware update 12.50?

I have been successfully using the Wi-Fi connection of my fenix 5 Sapphire for the last 18 months.

However, syncing now constantly fails with:

Connection failed. Try again.

I'm also unable to browse for other networks, the watch stating:

No Wi-Fi Networks Found

This issue seems to have coincided with the firmware upgrade to 12.50, although this may be a coincidence. Whilst the update was installed automatically via Wi-Fi, I did need to subsequently use Garmin Express to update the sensor hub to 6.50.

Can any fenix 5 Sapphire owners confirm that Wi-Fi still works for them post the update to 12.50?

Also, what is your Wi-Fi firmware version? Mine is currently at 2.40.

I have spent hours trying to resolve the issue. Despite me having made no changes to my router prior to the onset of the issue, I performed a factory reset on it. I have always had uniquely named SSIDs for 2.4GHz and 5GHz.

I have also tried changing encryption and specifying various fixed channels. I don't think the issue is with my router as all other devices continue to connect and I'm also unable to see any of my neighbours' routers from the watch.

I have attempted to delete and re-add the connection from the watch menu, from Garmin Connect Mobile and from Garmin Express.

I don't think there is a hardware issue as twice I have managed to connect. Once following a change to the Wi-Fi channel and the second immediately following a factory reset of the watch.

Finally, I have also tried reinstalling 12.50 via Garmin WebUpdater.

Would really appreciate any advice before I connect Garmin Support.