DC2591A Easy SMU - Touchscreen Problem

Hello,

I try to setup a SMU with Linduino and capacitive touchscreen (Adafruit 1947).
https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/dc2591a.html

12V is the supply and J3 set as EXT.
Unfortunately, my LCD shows just all white.
Even with USB connected.

When I test the LCD alone with Linduino (Graphicstest), it functions without any problem.
Over serial monitor I can see my commands are accepted and deployed when only Linduino and DC2591A are connected.

When I connect three and give e.g. LCD:DIS command, nothing happens. Still all white.

I suspect the sketchbook of DC2591A (Easy SMU Run) has not the driver completely.

Can it be true?