Phone no longer receives imessage banner/sound notifications since ios 9 update?

I have recently updated my iphone 5s to ios 9. After doing so, I no longer receive banners or sounds when I am sent a text through iMessage, only the badge above the app shows up.

I have tried; rebooting my phone several times, turning iMessage off and back on again, toggling all the message notification/sound settings off/on and resetting my network settings.

I receive notifications for regular SMS texts, mail, WhatsApp, Snapchat & FB messenger just fine, it is only affecting iMessage.

Has anyone else had this problem and knows how I can fix it or will I have to wait for another update for bug fixes?

Thanks.