UPDATE:

I tried a couple of things that I hope are helpful.
I took out and loaded another roll of PLA that has a lower extruder temp requirement. So, I set the Slic3r print to make the hotend 185 and the bed 80. It printed the part completely without any drop in hotend temp. The hotend remained stable at 185 through-out the print job.

Then, I went back into Slic3r and loaded my PLA settings for printing with a hotend setting of 185. I then changed JUST the filament temp from 185 to 210 and created the stl file. I loaded it on the SD card, and started the printer. As soon as the second layer started, the hotend temp dropped from 210 to 185.

While all this was going on, I monitored the voltage coming out of the power supply and it NEVER wavered from 12.4 VDC.

So....I have NO idea what to do from here!!