LCD glows behind screen, but won’t display anything right away

So, on my iPad Pro, if the device hasn’t been used in 10-15 minutes, there is an issue. Whether you tap to wake, click the power button, or open the Smart Keyboard, it will make the LCD glow, but no content just appears on screen. I then have to lock the iPad again by pressing the power button, and then unlocking it shows content, but the first time all you see is the glow of the LCD behind the display. I asked Apple but they’re clueless.