I am using IPB 2.3.6 and I meet a similar problem.
Document character set value in ACP->System Settings->Server Environment: UTF-8
MySQL charset: UTF-8 Unicode (utf8)
MySQL connection collation: utf8_unicode_ci
The collation of the database (all tables): latin1_swedish_ci
However, the collation for column title in table ibf_topics is utf8_general_ci
Title of an existing topic is: "Wonbin th