Known Issues: On High Sierra there are problems related to the screen brightness and sleep issues.
1. Reset SMC and NVRAM
SMC: https://support.apple.com/en-us/HT201295
NVRAM: https://support.apple.com/en-us/HT204063
Known Issues: On High Sierra there are problems related to the screen brightness and sleep issues.
SMC: https://support.apple.com/en-us/HT201295
NVRAM: https://support.apple.com/en-us/HT204063