Sorry to read the broadband stops working at a certain time of the day. I can understand how annoying this must be.
From checking your connection, the downstream power levels are too high and I would like to arrange an engineer appointment to adjust these for you. I've sent you a PM (purple envelope icon, right corner) with some details for you to confirm please.
This may not be the main cause of this issue, however it does need to be looked into. In the meantime, do you notice any lights change on the router at this time? Does it only happen on wireless devices, what about when connected through wired? As it happens at a certain time, have you got any timed devices that turn on/off at this time?