As you mentioned, it is probably because you made subfolders in the layout folder which isn't something you are supposed to do
However, there are plugins like this :
Which allow you to have virtual folders.
I encountered the same issue. I had to update my android studio to a version 3.6 or greater. It will resolve the issue.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.