ssd_mobilenet_v2_320x320 converting to Onnx

[YigitKaanBingol]

Hello everyone,
I've train ssd_mobilenet_v2_320x320 pretrained model with custom dataset via tensorflow2.x object detection api and exported to saved model with using exporter_main_v2.py. Everything works fine when inference it using tensorflow.
And then i tried to convert saved_model to onnx format for using in opencv readNet for some reasons.
But opencv gives error in :

cv2.readNet("model.onnx")
The error is : (-2215 Assertion failed) (bool) layer in function 'runLayer'
Onnx model looks weird in netron.

So anyone having the same issue?
Thank you for every answers or suggestions.