Looks like you have an old table with a different encoding.
Can you perform this SQL queries and share the results?
SQL:
SELECT character_set_name FROM information_schema.`COLUMNS`
WHERE table_schema = "YOURDATABASENAMEHERE"
AND table_name = "xf_ozzmodz_contactus_log_old"
AND column_name = "username";
SQL:
SELECT character_set_name FROM information_schema.`COLUMNS`
WHERE table_schema = "YOURDATABASENAMEHERE"
AND table_name = "xf_ozzmodz_contactus_log"
AND column_name = "username";
Replace
YOURDATABASENAMEHERE
with your forum DB name