“Black Screen” has happened on iOS 3 times in the last few days. I hadn’t used Legend on my iPhone for at least 24 hours today, to I started my phone, force-quit every app on it EXCEPT legend (which was still running in the background, then went back to the desktop. I then ’launched" legend (actually just bringing it to the front, and it had the black screen.
No other ‘apps’ were running on my iPhone when I brought it to the front, but they had been running previously.