Adventure 5M working until BT came along

We recently switched internet providers to BT, now anytime we try and send prints to our Adventure 5M all we get is "preparing to send. 80%" then it pauses and tells us to "check the connection"

i've tried -reconnecting it to the wifi -on and off again -factory reset the printer -forced it from the 5GHz to 2.4GHz -prayed to divine and fiend alike

any help would be much appreciated Thanks