I had the same issue (loss of WiFi connection without any indicator that there has been a disconnect, happens regularly, but with no pattern and the final straw, loss of Bluetooth connection). As this was a new purchase I called Dell and was given the instructions to uninstall Smartbyte. Bluetooth back and no dropout for the last six hours (yes that is a record). PC = Dell Inspiron 15 5570.
I hope this helps someone out there in Dell land.