One of the reasons why we at Zammad prefer postgreSQL
MySQL is a bit more caring in this regard. You need utf8mb4 whenever and whereever you want to use emojis. Flags especially like Hungary, Germany etc (so no plain ones) technically are emojis with patterns. This means they require more space.
This video does explain it pretty good. I’ve seen a german explanation somewhere from ccc, but I think english helps better here: