HDR Merging Problem

[NewAgePhotography]

Im reaching out to try and find away around a mergeing problem on Lightroom classic and lightroom CC when it gives me an error messege "Not enough matching photos for merging" even though they are the same photos with just a second of time between them. Im attempting to merge 9 photos taken with a nikon D5100 and a "Nikon AF-S Nikkor 55-200mm Dx" lens of stars taken last night. The settings I used for each photo were F/6.3, ISO:6400, shutter:1 second, Raw format, 4928 by 3264. Both Lightroom CC and classic formated the shots as .nef and I tried to perform an HDR Merge which as I said prior gave me the error messege "Not enough matching photos for merging". I tried the HDR, panoramic, and HDR panoramic just to see if it would work with any of them but it didnt. Next I tried enhancing all of the shots in both CC and clasic which made them into DNG's, I again tried merging, and in lightroom it merged only 3 of the shots but in clasic it didn't merge any. I would like it to merge at least 5 of the shots but I'm not sure what to try next. Heres a dropbox link to the 9 photos in case anyone wants to try for themselves 9 photo dropbox link. 

Thank you,

      NewAgePhotography

[JohanElzenga]

HDR is a technique where you merge a number of photos taken with different exposures, in order to create a photo with a higher dynamic range. Your photos were all taken with the same exposure. I assume you want to merge them to reduce noise, but that is not supported by Lightroom's merge options.

[NewAgePhotography]

Is that something that changed in a newer update? I use to do the same thing with photos simular to these and it would work just fine. Also do you have any ideas on an adobe softwear that dose support this type of merging?

Thank you,

       NewAgePhotography

[JohanElzenga]

AFAIK, nothing changed. Lightroom supports only HDR merge and panorama merge. This is neither one or the other. Photoshop supports stacking for other purposes.