Display turns off completely after a while in AOD mode

I have a watchface on :

  • Device Name: fenix 8 - 47mm, AMOLED
  • Firmware Version: 15.32

In AOD mode, the luminance is about 7.8%, and it passes the 24 hour burn-in test in the simulator.

However on the actual watch, the display continues to turn totally off after some minutes of being on.

Has anyone else seen this problem?