Ssd1306 OLED appears to be stuck on single line

Other Hardware Displays
4

I have not used the library for quite a while, so I had to look stuff up.

In the Adafruit GFX library is this function:

/**************************************************************************/
/*!
   @brief    Draw a line
    @param    x0  Start point x coordinate
    @param    y0  Start point y coordinate
    @param    x1  End point x coordinate
    @param    y1  End point y coordinate
    @param    color 16-bit 5-6-5 Color to draw with
*/
/**************************************************************************/
void Adafruit_GFX::drawLine(int16_t x0, int16_t y0, int16_t x1, int16_t y1,
                            uint16_t color) {
  // Update in subclasses if desired!
  if (x0 == x1) {
    if (y0 > y1)
      _swap_int16_t(y0, y1);
    drawFastVLine(x0, y0, y1 - y0 + 1, color);
  } else if (y0 == y1) {
    if (x0 > x1)
      _swap_int16_t(x0, x1);
    drawFastHLine(x0, y0, x1 - x0 + 1, color);
  } else {
    startWrite();
    writeLine(x0, y0, x1, y1, color);
    endWrite();
  }
}

Hopefully that helps.

Adafruit-GFX-Library/Adafruit_GFX.cpp at master · adafruit/Adafruit-GFX-Library (github.com)