I do have the following problem:
I imported many pics as JPG files, which contain GPS metadata and created collections etc. Now I added the corresponding DNG files so that Lightroom merges them. The DNG files contain no GPS metadata and thus now the GPS metadata is gone in the merged file which shows up in Lightroom.
How can I tell Lightroom 6 to use the GPS metadata from the corresponding JPG files without reimporting everything, which would require sorting the pics into the collections again?