Conflict between SD card and TFT screen

Hi everyone,

I am building a project where some data are read from SD card, and after being processed are written on a TFT screen.

The SD card is mounted on a simple module, and the screen is a 1.8" Adafruit display with the ST7735R driver. They both use the SPI interface.

When i run the program that read data from SD and after processing write them on the Serial Monitor, there are no problems. But when i add to the code, the initialization of the TFT, I can't read anything from the Serial Monitor.
All these instruction are inside the Void Setup(), in a while(file.available()) cycle. Even if I try to text something on the screen nothing appears.

But if i put the same instruction outside the while cycle, both the TFT and the Serial Monitor works.
I am sure that the file is always available.

Can somebody help me?
Thanks.