New Instinct 2S Solar surf will not connect to Garmin connect on two different Iphones

So frustrated today. My watch was warrantied with a  battery issue, got a new one, set it up and it just will not connect via Garmin Connect. The app finds the watch, it comes up and then I say "Connect it". It says "Completing the setu of your Instinct 2S Solar Surf device", shows a grey status bar that does nothing and then says "Pairing failed". I try over and over again. I've also tried:

-Resetting the watch back to default settings

-Connecting it to my laptop and updating it

-Deleting and reinstalling the app

-Trying with another phone (also an iphone) 

-Turning my hone and the watch off and on again

-Turning Bluetooth on and off 

And pretty much an obvious thing but no luck. Starting to think this new unit is faulty and it is such a mission to return it, took them 2 weeks to sort it out last time and only because I nagged, otherwise would have taken longer

  • The other watch with the same issue was deemed faulty, then they sent me another which is doing the same. I am no stranger to troubleshooting and figuring out electronic issues. I believe I have another faulty unit, clearly some issues with this model, as Federico has also experienced. I am busy discussing with support in South Africa who have been terrible

  • My faulty devices had serial numbers like 7440046xx, while the working device has serial number 7440052xx. Also the new device was already charged and with the firmware already updated.