Hi,
The method described several posts ago where you click on your sample folder and drag it into transfer is specifically how you get your samples to the +drive.
It sounds like the problem you’re having is with the method of how to access your samples on the +drive and then add them as sounds to the sound pool and the process is very specific because you need to save your sample as a sound.
Again, I will say this clearly, your sample must be saved as a sound, there is no getting around that. Your samples are not automatically sounds, that’s why I stressed the difference in my prior post, because you must then manually save a sample as a sound in order to use it as a “sound” in the "sound pool.
For importing samples into the sound pool, there is a very good description of the process right here in the post I quoted below, and this linked post is exactly how you access your samples in the +drive on a digitakt and then save them as sounds and import them into the sound pool:
Hopefully that will help some!