recently I bought a new Mac and installed the latest version of LR. I then imported a few files from an SD Card of my camera and I also have tousands of images from past years - those I have already exported as a catalog to an externad HD.
Since I have already transfered those "older" images from the original HD to a newer external SSD and then manually put those into LR via "add to catalog" I'm now missing all the development settings (like crop, contrast, HSL and other adjustments).
Is there a way to ONLY import the development settings from the catalog I have previously exported or do I have to remove the files I've added to LR via "add to catalog" first and then simply use "import fom another catalog" to import photos as well as developmet settings?
You talk about "the latest version of LR", but that means nothing. There are two versions of Lightroom; one is just called Lightroom (also known as 'Lighroom desktop) and stores its images in the cloud, and the other one is called Lightroom Classic which stores the images locally. Lightroom Classic uses a catalog, so I assume you use(d) that, but we need to be sure. If you use Lightroom Classic, then your edits are in the catalog. That means that you should not create a new catalog and add the old photos to it, but use the catalog from the old computer (https://www.lightroomqueen.com/how-move-lightroom-to-new-computer/). If you use Lightroom, then simply logging in with the same AdobeID should bring your images and the edits over to the new computer.