@vanilla_chief, Hi, welcome to the forum. Please read How to get the best out of this forum.
Please always post as much information as possible. It gets frustrating to have to ask back!
What processor did you use, link to the display (to make sure it is a board with booster circuit, level converter, b/w or 3-color etc.).
What constructor did you use, do parameters match your wiring?
What inking do you see on the flex connector (to compare to the panels I have).
What diagnostic information is reported in Serial Monitor (please put it into a code window), by which example?
Jean-Marc
Yes, it could be worth to try with the DESPI-C02. But if the panel works, you should be able to get it to work with the Waveshare board. You may need to use init() with shortened reset, and maybe use a different pin for CS. I would expect the panel to be the GDEM029T94.