Thanks a lot @JSWolf. The case I have is from kwmobile. They seem to be one of the few vendors making Libra 2 cases. I also found the Amazon page for Libra 2 cases with cases similar to the H2O case you have. The very majority of 3, 2, and 1 star reviews are complaining about auto sleep/wake not working as advertised. Mine doesn't work, either. It is kind of frustrating to find a case. This is a totally different experience from what I have with Kindle. Auto sleep function never fails with any Kindle cases for different models I have for the last ten years. Could it be that Libra 2 hardware is hard to design a case for? Or simply there is not much demand for a decent case for it. I did a lot of research on Amazon. Have not find any cases that doesn't have a lot of complaints about auto sleep not working.
https://www.amazon.com/kwmobile-Case...p?ie=UTF8&th=1