I'm already on my second 840 and with this one I'm having the exact same thing when it comes to syncing over wifi.
Failed, failed 9 out of 10 attempts probably.
I posted on version 24 or something and it still hasn't been resolved...
There have been posts about wifi since the release of this model.
Of course I've tried deleting networks, changing security, even without. Nothing works even 50/50.
With each update I still hope this annoying bug gets resolved. I've seen even in the Beta program that there are a lot of users reporting this problemand no response from the Garmin team
Do we have to understand that it's known that it can't be resolved? That it's more of a hardware problem?