I have the Inspiron 7590, and this issue has plagued me for a few months now. Occasionally without warning, the touchpad mouse will just stop responding. for a while I thought my computer was freezing, but one day I tried navigating with my keyboard and found that everything works except my mouse. It's almost as if the driver crashes.
Sometimes this happens when I unplug a USB mouse, sometimes it happens when I wake my computer up from hibernation, sometimes it just happens randomly. I looked in the device list to see about reinstalling the driver, but there doesn't seem to be anything in the device manager for the touchpad.
For a while I would reboot my computer to get the mouse working again. Then I discovered I could get it working again simply by putting my laptop into hibernation and then waking it back up. But while this only takes a minute or 2 to do, it's getting old after a few months of doing it two-three times a day.
It's not that the touchpad is somehow being disabled because I navigated to the mouse options using my keyboard and found that my touchpad was not disabled. I even used my keyboard to disable the mouse and reenable it in the settings, but my mouse still didn't respond. It's as if the driver has crashed and needs to be restarted. And at this point the only way I know how to do that (assuming that's what I'm doing) is to restart my computer or put it into hibernation and wake it up.