VivoMove3

I recently got my VivoMove3 back from my brother. I’m struggling to get it to sync with my phone. I get through all the steps, but when I press sync it says that there is a Bluetooth connection issue. This is strange because my watch is connected to my phone, the digital time is correct, but the analog is wrong. 

I’ve tried resetting it, factory defaults etc., but nothing is working. 

any suggestions would be great, thanks!