Could someone with PW2 5.4.2.1 try this:
- find an azw3 document. (if there is not then convert another one via Calibre)
- sideload this doc
- add this doc into a collection
- see if it is visible both on home screen and in the collection. (normally it should be visible only in the collection )
I know that on the home screen "sort according to collection" should be chosen.