Displaying JPEGs in Lightroom Classic

I find that my new LR Classic (and my now-deleted LR5 also) only shows RAW photos in the Library. I work from the hard drive where photos (RAW and JPEG) have been categorized by location for Travel Pix, or by year/event for Family Pix. (Probably ought to rethink that but suspect it's too late.) Anyway, when the folder is chosen in Library only RAW shots show; JPEGs merely have framed blank spaces showing. The indicator arrow to open the folder is partially grayed out if there are JPEGs within. Where a folder has only RAW shots, the arrow is black. This was not always the case, I think.

How do I gain access to JPEGs and show them on the Library along with RAW?

Thanks,

Chris