Waveshare e-paper displays with SPI

Hi,
i use a waveshare 2.9" with an esp32.
First of all: thanks for the library and the example sketch.
I know ZinggJM have currently no experience in drawing bitmaps on the display.
Maybe someone can help me.
I already have running the gxedp library and the example sketch. Ich can show bitmaps in fullscreen and text at all. ( display.drawBitmap(BitmapExample1, sizeof(BitmapExample1)); )
But when i try to show particular bitmaps ( display.drawBitmap(0, 0, BitmapExample1, GxEPD_WIDTH, h, GxEPD_BLACK); ), the bitmap always shows mirrored.
In the libraries itself i didn't find any hint to this.
maybe someone have an idea?
thanks.