Thanks for the responses.
Forgive me for any errors i make as long as i am new to arduino.
When your LCD is using the SPI port, it can get interrupted by the radio's ISR
At the time of the experiments, i get strange white pixel dots only when i use "if (radio.receiveDone())".
Firstly i fill the screen with black "tft.fillScreen(ST7735_BLACK);" and then i add a delay(5000). But when radio.receiveDone executes first in loop(), the only function in loop, i get white pixels on top-left of lcd. So i think interrupt has no rule for now because i have finished writing to LCD (am i correct?).
Looking in the libraries i see that RF69 unselects SPI. The LCD (*csport |= cspinmask; ) does the same thing after writing to SPI.
The strange i discovered is that when i set LCD pin slave select to HIGH the lcd still responds to commands.
ex. in fillRectangle
Sorry again if i cannot explain it so to understand it.