m15 R5, sometimes restarts automatically after shutdown

Update: I found the below solution from the internet. The issue has not happened since I followed the below steps. Hopefully it is a permanent fix. Below the solution, I included a note/warning re: Dell's approach to support and my opinion of the entire experience. Again, I'm hoping there isn't any more issues but hopefully everything is taken as constructive.

Solution from other website (link). Specifically, I determined the device that kept waking up my laptop. There are other solutions offered on the page that is why I included the link. 

If your computer keeps on waking up or booting up by itself, what you need to do is understand what triggered it. To find out what woke up your computer, you can run a few commands using the Command Prompt.

To do this:

1. Press Windows + X and choose Command Prompt (Admin) from the menu. This will allow you to open an elevated Command Prompt with administrator rights.
2. Type in the following command, then press Enter: powercfg –lastwake. This command will show you the last device that woke your computer up.
    

    

3. Next, type in this command, followed by Enter: powercfg –devicequery wake_armed. This command will show you a list of all the devices that can wake up your computer.
    

    

4. Exit the Command Prompt.

For mine it was my bluetooth mouse connected via USB dongle. I disabled the feature under Device Manager>Mice and Other Pointing Device>Power Management (tab)> unchecked Allow this device to wake the computer.

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Feedback to Dell / Warning to others: 

It was very difficult to find a way to get support for my brand new laptop. 

After posting here the first Dell support rep was kind and courteous through the direct messaging. We tried one thing but as I mentioned in my post the issue doesn't happen all the time. Apparently, there's a rush to "close" tickets but "I could always" re-open.

Unfortunately, after a few days, the issue happened again and I reached out as instructed. The next rep (or reps, not sure how many) immediately suggested doing a complete restore of the OS. How is this troubleshooting? As I mentioned via direct message to Dell, the laptop is new, I only installed the updates as prompted by Windows Update and Dell's Support Assist app. If I had blindly followed instructions, I believe the issue would still reoccur as the same factory settings would remain. 

TO DELL: Stop immediately suggesting people should re-install the OS without having done some basic troubleshooting first. Hopefully what I found on the internet did fix the issue. If not, I will definitely come back here and maybe eventually try doing the restore. As it stands the Dell rep who suggested this should be re-trained as it is evidence of "lazy support" which leads to terrible customer experience.