YOLOv3, tiny-YOLOv3 weird bounding boxes on Iphone X

[TheXeniL]

I'm having trouble with recognition of objects on iPhone X (and iPhone 6s as I tested it) using the YOLOv3-CoreML. Not changing anything in the code gives weird results as you can see in the picture below:

Using the predict() function, it appears that iPhone X recognizes objects like the umbrella and others with 100% confidence. Changing confidenceThreshold and iouThreshold doesn't give any effect, as well as changing maxBoundingBoxes to 1-5. Using predictUsingVision does not produce any prediction at all on the screen.

The same problem I get with tiny-YOLOv3, YOLOv2 with custom and original models from Darknet using iPhone X.

However, using the same code on iPhone 6 (not s) produce an absolutely opposite result. It can predict objects successfully (using predict() function) with my custom model and original Darknet models:

I assumed that there is a problem with GPU changes Apple did start with iPhone 6s devices, but I haven't found any information about that. Does anybody have an issue like this? Did anybody try using the code on iPhone X device? I explicitly decided to test the code in the repository without any changes to provide a demonstration, the problem isn't about YOLOv3 or tiny-YOLOv3 or even YOLOv2 - the result is the same for me using any YOLO version.

You can find videos demonstrating the work on iPhone 6 and iPhone X:

iPhone X: https://imgur.com/a/EZOpr1W

iPhone 6: https://imgur.com/a/qQZtJAd

I will appreciate any help and assumptions you can provide, but as far as I tried to solve the problem for two weeks I didn't get the result, I wonder if there a positive cases using the code on iPhone X by other people.

[MichaelScaria]

How did you generate a CoreML model with tiny-yolov3?