Hard to say. I have 2014 and 2015 MBP 15s and a 2015 MBP 13 and I've hooked them up to external monitors, sometimes with the lid closed and have never seen this problem. What happens if you open the lid before detaching the external display? What's the operating system?
It's probably some kind of software "glitch" that results from unplugging the external monitor at work while still in "clamshell mode".
What I would try:
(and no, this doesn't "resolve" the problem, but merely "works around" it):
1. When done at work, open the lid.
2. NOW disconnect the external display.
3. Does the display go "back to normal"?
4. If so, close the lid and take it home.