Iphone 6 is dropping bluetooth pairing with Tom Tom rider 400?

Hi there, I'm having some issues trying to connect my iPhone 6 with my new Tom tom rider 400. Connection gets established pairs and few seconds later drops, then comes back and again drops....anyone have any solutions? i know apple is not that good with their bluetooth connectivity with anything but this is a bit frustrating as gps uses live data from it...any help much appreciated 🙂