I'm running out of ideas.

BackupManager/Program.cs

@@ -110,6 +110,9 @@ namespace BackupManager {
             using (MySqlConnection conn = new MySqlConnection(connStr.ToString())) {
                 conn.Open();
 
+                using(MySqlCommand comm = new(@"SET NAMES 'utf8mb4';"))
+                    comm.ExecuteNonQuery();
+
                 using(MySqlCommand comm = new MySqlCommand(@"SHOW DATABASES;", conn))
                 using(MySqlDataReader read = comm.ExecuteReader()) {
                     while(read.Read()) {