Playin can nnot link decoder

[Mohammad-AL.Gmail]

Hi,

I using a decoder designed by our supplier.
Gst-inspect lists the decoder
Gst-launch filesrc can playback the media file
But gst-launch -v playbin2 uri    approach can not play the file
Looking at the dot file I find the decoder is not added to the deodebin2.

What could be the reason / possible reasons for this difference of
behaviors?

Thanks and
Kindest Regards,
Salim