Error during prediction within coreML framework of the converted Efficientdet-lite0 model

[Jsbie]

As described in issue posted on coreML forum: https://developer.apple.com/forums/thread/730922 I successfully finetuned efficientdet-lite0 model, run it correctly on python, converted using coremltools (tensorflow==2.12.0 and coremltools==6.3.0) to mlmodel format and loaded within coreML framework.

However, during prediction I receive following error:

2023-06-05 09:10:56.942952+0200 xxxx[1619:435597] [espresso] [Espresso::handle_ex_plan] exception=Espresso exception: "Invalid state": Stack_nd layer: Invalid shapes of input tensors. status=-5
2023-06-05 09:10:56.943016+0200 xxxx[1619:435597] [coreml] Error computing NN outputs -5
2023-06-05 09:10:56.943088+0200 xxxx[1619:435597] [coreml] Failure in -executePlan:error:.
Unable to classify image.
The VNCoreMLTransform request failed
Error: Vision request failed with error "Error Domain=com.apple.vis Code=3 "The VNCoreMLTransform request failed" UserInfo={NSLocalizedDescription=The VNCoreMLTransform request failed, NSUnderlyingError=0x2801267f0 {Error Domain=com.apple.CoreML Code=0 "Error computing NN outputs." UserInfo={NSLocalizedDescription=Error computing NN outputs.}}}"
2023-06-05 09:10:56.991190+0200 xxxx[1619:435607] [espresso] [Espresso::handle_ex_plan] exception=Espresso exception: "Invalid state": Stack_nd layer: Invalid shapes of input tensors. status=-5
2023-06-05 09:10:56.991256+0200 xxxx[1619:435607] [coreml] Error computing NN outputs -5
2023-06-05 09:10:56.991285+0200 xxxx[1619:435607] [coreml] Failure in -executePlan:error:.
Unable to classify image.
The VNCoreMLTransform request failed

Is this related to last, 'detections' layer that stacks results of the inference?

Has anyone managed to run efficientdet-lite0 or any other model from this repository on iOS? Any help or suggestion would be really appreciated.