When this happens, you can try disabling and enabling the wifi card in the Device Manager.
Recently, when I keep my laptop closed for some time, it disconnects and disables my internet automatically and need to restart for establishing the internet again. I have kept my power settings to default to keep everything on. Is there a way to keep everything in on condition, even after closing the lid?
XPS 15 9570 disconnects internet after closing lid but works fine after restart.