If so, select the Camera, Lens and Profile, then go to the Setup: pulldown and select Save New Lens Profile Defaults. Try another image. Is it automatic now?
Can you upload an original raw file (NEF) taken with the lens that doesn't match the correct profile to www.dropbox.com and post a public download link in a reply, here, so someone can take a look? The 150-600 profile has been supported for Nikon since LR 5.3 so a couple years ago, and sometimes lens firmware updates cause a lens to become unrecognizable, again. An example image would be useful to determine this.
Can you also try importing just an NEF w/o converting to DNG and see if the lens profile works, that way we know if it is something with the lens or the DNG Conversion that is causing an issue.
Stephan, please (if possible) upload a sample image (NEF) as Steve suggests and I will confirm the fix works with your images.
So sorry. I rushed and overlooked it. Please find the links attached. I used OneDrive, hope that doesn't matter, I don't have a dropbox account.
Appologies and best regards
There are three profiles listed: VC A011E and VC A011N seem the same and non-VC A011S. I am not sure why there are so many versions but maybe a specific profile isn't being used because Adobe cannot tell which of the three (or at least of the two VCs) it should be.
If you look at my reply to Rikk's and his, earlier in the thread, you'll see how to have LR default to the right lens instead of saying None by customizing the LR Lens Setup to Default instead of Auto and also saving profile you choose after clicking Tamron as the Default profile for that lens in LR.