I'm having this same issue and it's extremely frustrating. Sometimes it will come in and out of view while just staying idle on the page.

im getting a black background when I call DeviceActvitiyReport(.init("...")) no matter what I do. It seems to be overriding (generating on top of) any background i set that view. any ideas?

I should have put this in the post, but yes, I am aware that you have to test on device since iOS Simulator doesn't track device activity. In my case, even trying to shield all selected apps with intervalDidStart doesn't work on my device so I am definitely doing something wrong.

Just a point of note, I understand the code is a bit messy and that there is probably redundant code; I apologize, I ended up just trying a bunch of kinda random things to try and get it to work :_)