My fairphone has an issue where sometimes (maybe once a day) when waking the phone, instead of showing the lock screen background, the screen is black. The status bar is still showing, however. I cannot unlock by swiping the screen up, as i normally would, but I am able to unlock my phone by draging down the status bar and long pressing a setting (bluetooth for instance). This prompts the pattern to unlock the phone. The issue persists the next time i lock my phone.
I have found two fixes: rebooting the phone, or attempting to making a phone call (i hang up immidiately before the connection is started). I will check whether it is my launcher that creates the issue (Nova Launcher) and come with an update. In the meantime, if anyone has experienced anything similar please reach out!