Database: retail_complains
Question: What was the detailed issue did Mr Gunner Omer Fuller complain about?
SQL: SELECT T2.`Sub-issue` FROM client AS T1 INNER JOIN events AS T2 ON T1.client_id = T2.Client_ID WHERE T1.first = 'Gunner' AND T1.middle = 'Omer' AND T1.last = 'Fuller' AND T1.sex = 'Male'