ILI9488 in RGB Mode

[MaTech]

I'm working on a project involving a TFT LCD with an ILI9488 Driver (This Model: https://www.buydisplay.com/default/serial-spi-3-5-inch-tft-lcd-module-in-320x480-optl-touchscreen-ili9488).
As mentioned in the Subject I want to run the LCD Driver in RGB Mode in conjunction with an PIC32MZ2025DAH176.

To do, so I have to select the correct Mode (RGB) over 3-line SPI with 9bit (Bitbanged) that works fine and shows also as the correct Data on both my Scope and on my Logic Analyzer.
If I read the registers back everything looks as expected, but when I activate the RGB signals in my case I'm using the Graphics Stack with the GLCD Controller in MPLABX Harmony I got nothing back over SPI.

I also watched that certand registers can only be edited when the corresponding Lines (YSYNC,HSYNC,...) have the right states (HIGH?). I implemented these states, but I still can't get anything over SPI when using the Graphics Stack.

Has someone tried using this Driver in RGB Mode before or has Experience with the Graphics Stack in Harmony maybe their is something to change??

Thanks in advance.