MolView is unable to generate correct 3D structure for hydroxypropadiene
I suspect MolView simply fails to parse the compound's name you are trying to input. "Hydroxypropadiene" isn't the proper name, at least not by IUPAC standards. According to Google services, this name doesn't appear in any textbooks and is mentioned only in three research articles from 1980s.

The PIN propa‐1,2‐dien‐1‐ol appears to work correctly with MolView:



When you are trying to get a 3D image from the 2D drawing, there is the following issue which MolView usually reports (not sure why you haven't received the message): 


  Failed to load structure from sketcher. This structure may contain allenes, which cannot be represented in the SMILES notation.


MolView relies on SMILES in order to fetch the 3D structure.
The problem is likely that Ketcher generates wrong SMILES because PubChem indeed receives C=CC=O instead of the proper one, C=C=CO.