u/rSoPtUmN

These pictures were taken after washing. 

(I did not include the washing procedure intentionally. I was unclear if describing my washing process in detail would violate the community rule on synthesis.) 

Picture number one shows a powdery like substance adhered to the wall, bottom and even on the precipitated product. This powdery substance is absent in picture 1A, which is the normal result I get. 

This unknown substance will dissolve in warm isopropanol. 

Has anyone else encountered this?

Does anyone have any thoughts on what it might be and subsequently how to get rid of it. 

Thanks.