It seems you have some screen filtering app such as Twilight or Lux installed on your system. Please refer to the steps given in the document Troubleshooting: Buttons not working in 16.2/16.3 version to solve the issue.
Adobe Acrobat Team
Thank you, it worked.
I'm using Bluelight and it doens't have the exclusion list. Hope it will come back as it was..