When merging raw photos to produce a raw DNG result, the data is still raw, and you cannot have different settings applied to source photos to produce the raw result. At best, one of the photo's settings are applied to the final DNG as its initial settings, and in my experience the settings of the most-selected photo you've right-clicked on before choosing Photo Merge->Panorama... is the one the settings are used from.
The six images you have selected appear to be mostly duplicated in pairs. What happens if you just select the 3 CR2 files that overlap the least, say 2, 4 & 6, in the grid you have, above?
The white and missing tree at the left edge almost looks like something wasn't matched up correctly and maybe it's sky or clouds over the top of where the tree should be.
Can you upload the source images (at least the 2, 4, 6) to somewhere like www.dropbox.com and post a public share link to them, here, for others to try?
The images you upload to dropbox are only shared to people who know the link, which are only those who read the post, there, and you can remove the images at any time, making them inaccessible to everyone, again.
If you can't share image, then you can experiment with them, there and people can make comments based on what you've done and say about it but that's about it. For Adobe to fix something they would need to reproduce the issue.
At this point, my guess, is that you're supplying too many images and LR is confused so the results are non-optimal, although something may have changed with this release so there might be some tweaking Adobe needs to do.
Try merging just the TWO images in the new LR that the old LR version is choosing to do it's merge from and see if that works.
I'm can't be sure why yours isn't working without seeing the files (a private dropbox link doesn't give access to any more folders), but it appears, judging by how bent and warped your final file is that the panorama wasn't shot around the nodal point and/or not on a tripod, with also possibly not enough overlap on the right-most image. Panorama's that are shot correctly tend to look like a normal rectangle (when using a telephoto) or a continuous curve (when shooting wide angle), not rolling hills as above.
Maybe this makes sense?