Now, I'm getting a partially rendered image (only the top 8-10 px or so - the rest is white/blank), and this message in the debugger
-> same as you.
It seems that UIGraphicsImageRenderer causes this bug. And I solved it by old codes. How about this code for you?
let cropRect = mapVC.view.frame.inset(by: mapVC.view.safeAreaInsets).inset(by: mapVC.mapEdgeInsets)
UIGraphicsBeginImageContextWithOptions(cropRect.size, false, 1.0)
mapVC.view.drawHierarchy(in: mapVC.view.bounds afterScreenUpdates: true)
let img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()