I had made similar experience. Some photos, less than 20%, have been transferred on begin of March - nothing happened since.
Interesting is that photos had been transferred mainly from five specific locations, with quite big time gaps in between. But not even those blocks were complete.
All transferred photos in the google archive have the same date, of the transfer day - what a total disaster!
So after not transferring the photo location, and not transferring the categories, they also failed in something as simply as keeping the photo date.
Another prove that the G-Maps team is completely unwilling and unable to do any job right related to Panoramio.