@Thody Well done. That was probably a hit or miss operation - and it was a hit ? Modded FW release can be shared via Google Drive or MediaFire link. I believe that you can also attach it to your post...

@Debi568 Update the RE firmware first and then follow my post suggestions - here. How to update RE firmware - details.

@Midori Go through this thread for more details on that matter.

@JC2024 AFAIK Synology has a certain certified network adapters which are recommended to work with their hardware. Check the optional accessories in the Synology 1821+ spec section here (bottom of...

@Debi568 You didn't mention what's your host router ? Reset the device by pressing the reset button for about 10 seconds and try again. If this still doesn't work for you, try this troubleshooting...

@Debi568 What make and model is your host router ? WA850RE supports only 2.4GHz wireless band. When you running through the procedure do you see the host wireless networks available in the list ?