XPS 13 9343 (2015 model) - Cannot restart when lid closed and connected to external monitor via mini DisplayPort

Just found a very interesting problem.  I just purchased a new 27" monitor and connected to my Dell XPS (9343) using a mini DisplayPort to HDMI cable.  The laptop was on and running when I connected everything and closed the lid.  Everything was working beautifully, until I ran WIndows update and had to reboot.  Then all *** broke loose.  The machine started beeping like crazy and the battery charge light started blinking orange then white and then it shut down.  After I recovered from my almost heart attack (I thought my laptop had died)...I opened the lid and hit the power button and it started up fine.  I closed the lid after it rebooted, and continued to work fine.  So as a test, I restarted the laptop again with the lid closed while the external monitor was connected and again the beeping and the orange light blinking.  Proceeded to turn it back on with the lid open...everything fine.  I checked the BIOS settings and everything seems to be normal.   It seems there's a problem with this laptop not being able to be restarted in the closed lid position when an external monitor is connected (something I do ALL THE TIME with my Lenovo work laptop that is also connected to an external monitor).   Has anyone else had this problem?  Is Dell aware of this issue??