SOLUTION FOUND! I have a MacBook pro with the same issue. I found connecting and external monitor or TV with the HDMI cable corrects the issue. I then purchased a CompuLab Display Emulator on Amazon for $8.50. It's a small dongle you connect to your HDMI port. It fools the laptop into believing it has an external monitor connected. The dongle eliminates the need for the external monitor. Better than an $1100.00 board. I put the link below.
P.S. I tried all of the solutions out there and none of them worked for me.
Best Wishes to you all,
Port
https://www.amazon.com/gp/product/B00FLZXGJ6/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1