I don't have much to go on here except your text. What you told me is just that it disconnects and I can cause that to happen if I power up an old router at the office. WiFi is subject to interference and odd things like a machine that will drop and the other does not.

This is not news. But how to fix is a bit of a sleuthing job. For me I pull up my android phone and run the WiFi analyzer to see if the area is cloggeed and then try changing the router WiFi channel or if it has it, AUTO select the channel. After that if it's just one machine, you try some USB WiFi stick to see if the internal has gone south.

There are more posts with tinkering with power savings and folk that run torrents but that's well done. Here we only have what you can share.