Hello, i think i can help here.
Do you have a Laptop? Wifi is run off the Intel Chip and when you use too much of the performance of a Laptop, it will lag the wifi causing interference and disconnection. I had a similar issue on my 2012 Lenovo laptop and had to do some investigation. The CPU usage is the issue here.
Same with a PC if you use an Integrated Wifi chip instead of a Hardware one.
(WiFi chip are manufactured by Intel)
You can also validate that the Router isn't a problem with a second device. That device will still have access to the internet with the wifi.
I hope it help.