Bluetooth Bowers & Wilkins Headphones No Longer Automatically Connected

Ever since I upgraded my iPhone 6s to iPhone X, my wireless bluetooth Bowers & Wilkins headphones (P7) are no longer automatically connected.

They are recognised as device, but the connection status remain "Not Connected" until I manually tap on the message and that's when they connect.

This extra step was not necessary on my iPhone 6s and as soon as I turned my headphones on, they were after around 2 seconds connected to my phone. Has anyone else experienced this issue?

Suggestions are welcome.