is it for all OTAs or just a specific one? I had a similar issue not too long ago and it was booking.com only, I had to manually re-open the category in extranet. You will have to disconnect Mews to manually open them and then connect again if you’re using the integration. I did inform the support team before I disconnected so they knew there would be a request to re-connect and they could react quickly when it came. 

Thank you, I have managed to reslove, the room wasn’t mapped, although it doesn’t explain why it was able to be booked up to the end of the month.