TouchGFX syncronisations timer interrupt is not called

[FDick.1]

Hello, 

I am currently trying to control a TFT display (240x240 pixels) with SPI. I have followed these instructions: https://helentronica.com/2021/01/22/touchgfx-on-a-custom-made-low-cost-board-with-the-ili9341-controller-over-spi/ 

I have a different display driver (ST7789) and a STM32F429I disco board. I took a ili9341 lib and customized the registers because I didn't find an adequate lib for the ST7789 that included "SetWindow" and "DrawBitmap". The instructions include a timer interrupt which is called every 30ms. But in debug, it can be seen that the program goes through the MX_TouchGFX_Process() routine over and over again and never goes into the timer interrupt. Accordingly, the image created in TouchGFX is a white box and a button is not displayed. I don't have touch on my display yet, is that the problem? I would have thought the display should still work. CubeMX adds the function MX_TouchGFX_Process() to the while(1) of the int main when I want to work without OS. I'm still too complex about RTOS and wanted to get it working without it first, which should be doable in principle. Can someone help me? I don't understand why the timer interrupt is not called.