On windows 10, I have created a folder 2017 in lightroom. It exists in file explorer but does not appear in lightroom. When I want to download files from my camera , the folder appears in the download dialogue bot after the pictures are downloaded into lightroom, they show up in individual folders by date but not in the folder 2017, which is not visible in lightroom. The daily folders sre in the 2017 folder in file explorer. This appears to be a lightroom problem.
If you are importing all the images from that folder, Try synchronising the folder in Lightroom and see if that helps.
Turns out that lightroom was not showing the parent folder for these files. When I selected show parent folder , everything is displayed as expected.
Thank you for your quick response Akash.