Internet constantly disconnecting and speed deterioration
This is my first time using this forum, so I hope I'm in the right place to ask this. We're currently experiencing some really bad issues with the internet (or router) constantly disconnecting. We are currently using the BT Home Hub 5 with BT Infinity, and for some reason the internet keeps disconnecting, and the speed keeps deteriorating. Almost every time the router drops out it gets slower by at least 5MB... until it gets as low as 10MB when we should be on a 40MB connection.
I've spoken to BT on the phone and an engineer has already been out, where he tried every possible test and also fitted a new socket, a bit of new cable and tried to fix the signal to noise ratio problem. I thought that would help but the problem has continued and even after speaking to another BT representative on the phone, who just told me not to have too many devices on the network (when it does it even when only one device is connected), told me to change the 5GHz channel to a different one and to monitor my connection for 48 hours and get back to them if it doesn't fix itself.
Just to make things clear, this isn't a wireless issue, this happens to the internet as a whole, even the wired connections drop.
What do I do from this point? I'm pretty sure that monitoring it is not going to change anything, and I don't know what else an engineer could do.
Does anyone know what this could be likely due to?