LR will only recognize 1 folder on external drive.

In trying to get LR to recognize an external drive I imported a photo from 1 folder (2019) and it now will recognize that folder but not the rest. Shouldn't recognize the whole drive now and not just one folder? And, I've tried to get it to recognize another folder the same way but it won't do it now. I'll import a picture from another folder and all I get is that 1 picture. I've tried restarting lightroom but nothing. I've spent 3 hrs tonight combing the internet to no avail. Help