Unfortunately MySQL’s utf8 charset does not completely allow all possible UTF-8 characters, in particular Emoji. They created a new charset and collation called utf8mb4 that allows for emoji to be stored but tables which use the utf8 charset, and connections which use the utf8 charset will not use this.
Please run gitea convert, or run ALTER DATABASE database_name CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci; for the database_name and run ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci; for each table in the database.
You will also need to change the app.ini database charset to CHARSET=utf8mb4.
