1708 Fail of "Sync files to:" change

[chrisjj]

On a fresh-formatted MTP device:

1 Change to "Sync files to:" Music:
2 Auto-sync
3 Inspect device

Expected: specified locations
Observed: some locations not as specified e.g http://i.imgur.com/sSr4Rx4.png
or no locations as specified http://i.imgur.com/tooD9le.png -> http://i.imgur.com/czDnib9.png

Perhaps MM is failing to update some cache of transfer information, perhaps when it finds the device is not empty.

Workarounds:
1) After change and before sync, exit and launch MM
2) Apply [x] Enforce use of sync mask for files already on the device http://i.imgur.com/JtY4x3g.png