I've seen a few posts relating to devices being disconnected from people's home networks, but I'm not sure if I've seen the solution. In our case we have been with BT since April (after 14 trouble free years with Sky) and the following is an example of what happens frequently on our network:
PC I am working on (ASGA54743) is disconnected from the network and therefore loses internet connectivity. Almost 2 minutes later it decides to reconnect. As a home worker this is particularly annoying as I can be in the middle of something and for no apparent reason I am disconnected. At the same time my other PC, phone etc are still connected without issue. However, they will probably be disconnected another time when my work PC is ok. So annoying.