Bidirectional "SDA" display pin connected to "MOSI" on ESP32 board doesn't read from display.

[Tom1304]

I successfully attached a 240x240 ST7789 display (GMT130-V1.0 display ,ST7789VW 1.3" 240x240) to a ESP32 WEMOS D1 mini 32 board.
Everything is working fine until I try to use exisiting background while rendering smooth graphics instead of forcing a background color.
For example the
drawWideLine(5, 50, 200, 100, 10, TFT_BLUE, TFT_BLACK)
is working but
drawWideLine(5, 50, 200, 100, 10, TFT_BLUE)
does not. The application simply "hangs" in this call forever.
I enabled the TFT_SDA_READ flag but the read from SPI doesn't seem to work.
Do you have any idea of how to use SDA connected to MOSI for readings?

My build flags are as follows:
build_flags =
-D USER_SETUP_LOADED=1
-D ST7789_DRIVER=1
-D SMOOTH_FONT=1
-D TFT_MISO=-1
-D TFT_MOSI=23
-D TFT_SCLK=18
-D TFT_CS=-1
-D TFT_DC=2
-D TFT_RST=4
-D SPI_FREQUENCY=40000000
-D SPI_READ_FREQUENCY=20000000
-D TFT_SDA_READ=1
-D TFT_WIDTH=240
-D TFT_HEIGHT=240