Potensial bug in GxEPD2 for 7.5in HD 3 color GDEH075Z90 e-paper, combinded red and black

For whoever would like to report a Potensial or real bug, you are welcome.

But I need complete information. Links to devices in question, wiring, connection module, inking on the panels flexible connector.

I don't see any Waveshare e-paper display with screen dimension of 880x688.
-jz-

I forgot to mention, any newbie should first read:
https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/681314/1