Sqlite-net exception: unable to close due to unfinalized statements or unfinished backups

My app uses the sqlite-net library - the version that is based on SQLitePCL.raw. During app shutdown, it randomly (about 50% of the time) throws this exception. It is thrown by SQLiteConnection.Close().

I've come across this bug report and this one. The first has no response and the proposed fix in the second one does not help.

Questions:

1. Why is this exception thrown? Please provide as much detail as possible.
2. What does app code need to do to avoid it? Is it a bug in SQLite-net?