I just noticed a bug, for Items Marked ‘Is purchase Item’ only, it is showing in Sales Order and Sales Invoice. I checked Purchase Order and Purchase Invoice, ‘Is sales Item’ it is getting filtered out.
I am sorry Umair, It was error in my custom script, When you mentioned you could not replicate it I had a feeling it might be the custom script. I will fix my code.
Thanks for your help. I will Comment in the Github issue as well.