EDIT: Solved- thanks guys
So I recently bought a SoundCore2 (from Amazon UK), when I first used it with my iPhone 5S, it worked. I then tried to connect it to another phone, worked then as well, it was only after disconnecting from this phone that it wouldn’t work on my iPhone, it works on every other device I paired it with apart from my iPhone (including other iPhones). Anyone else had this issue or is it a case of exchanging it if it still doesn’t work?
Cheers