The HAP-Z1ES firmware could be rolled-back to the previous version "press and hold the Home Button while turning the Unit on, you will see the light above the power button flash a few times and then hear a click and it will stop flashing, it will turn on the Special Mode (in the display menu), choose the 3rd option down and it will roll-back to the previous version firmware".
My set-up (HAP-Z1ES via USB into Devialet Expert 400) will not work with the current 0018120R version firmware, but works fine with the previous 0018033R version firmware.
My set-up (HAP-Z1ES via USB into Devialet Expert 400) will not work with the current 0018120R version firmware, but works fine with the previous 0018033R version firmware.