Strange Indexing

volumio index.pngI just added a new folder to my hdd and for some strange reason volumio insists on rearranging the songs. Actually it has happened twice - the two newest folders I added. The screen shot shows the way the files appear in volumio and file manager. I do note that volumio is displaying the song title from the EXIF rather than the file name from the folder. I have edited the EXIF file on all songs so that the track info is correct and I named the files with digits first to ensure correct order. Nothing seems to work. If I attach my hdd to my (Linux) computer and play the folder contents with Audacious, it plays in the correct order.
Does anyone have an idea what volumio is doing? and how to fix it?
FWIW, I am using it on a Pi2 with Library view turned off and have just asked it to check for an update and none was found.