When your camera is set to capture in RAW+ so it is recording not only the RAW image but also a JPG image to match you may find that Lightroom shows you only the RAW version of the file.
This is because Lightroom, by default, treats the RAW version and the JPG images as one.
However, if you want to deal with them separately, choose Edit > Preferences (Lightroom > Preferences on the Mac) and select the General tab and select the option: “Treat JPEG files next to raw files as separate photos”.
Now Lightroom will treat the RAW and the JPG images as being different images so you’ll see both images in your Grid, Loupe and Filmstrip views.