See https://meta.wikimedia.org/wiki/Grants:Project/ScienceSource as an example. Using any of the above buttons to create a page as a part of a WMF Grant project results in a window to edit the Main Page on Meta:

Same result using a simple inputbox on my talk page:

This appears to be a general issue with the extension rather than a issue with a particular instance. People cannot create pages for grant reporting or other cases in a straightforward manner unless these buttons work properly.