ONNX loading error after conversion from Tensorflow 2 - Inconsistent shape for ConcatLayer in function 'getMemoryShapes'

C++
8 
net = cv.dnn.readNet("model.onnx")
image = cv.imread(cv.samples.findFile("classroom__rgb_00283_1024.png"))
image_mod = cv.imread(cv.samples.findFile("starry_night.jpg"))
paramSAMEncoder = cv.dnn.Image2BlobParams()
paramSAMEncoder.datalayout = cv.dnn.DNN_LAYOUT_NHWC;
paramSAMEncoder.ddepth = cv.CV_32F;
paramSAMEncoder.mean = (0,0,0);
paramSAMEncoder.scalefactor = (1, 1 , 1 );
paramSAMEncoder.size = (480, 640);
paramSAMEncoder.swapRB = True;
paramSAMEncoder.paddingmode = cv.dnn.DNN_PMODE_NULL;
blob_opencv = cv.dnn.blobFromImageWithParams(image, paramSAMEncoder) 
blob_opencv2 = cv.dnn.blobFromImageWithParams(image_mod, paramSAMEncoder) 
net.setInput(blob_opencv, "placeholder")
net.setInput(blob_opencv, "placeholder_1")
blob = net.forward()