collection@sp for a collection created when the locale has been set to es-es,
collection@sv is a result of creating collections when the locale was set to sv-se and so on.
Today I changed the locale thrice, every time creating a collections, and after importing, these collections appeared without suffixes. Maybe the reason is that I haven't restarted the device, since the collections I created previously still have the suffix, even to delete and to re-import them.
I'll continue testing the app and describe if possible the logic of creating and import collections.