Wrong sort order using utf8_unicode_ci and swedish characters like ö
Interestingly, someone addressed this apparent difference.

Matthias Bynens answered the post MySQL Collation utf8_unicode differences abour 4 years ago.

He mentioned "Weight Keys"


version-4.0.0 UCA weight keys
utf8_unicode_520_ci is based on UCA 5.2.0 weight keys


For more information, go to The Unicode Consortium.