RDS Mariadb instance, crazy storage consumption

i had a problem with my instance with 200gb space and 24gb used... suddenly (with no code uploaded and structure modification) throw message "Error Code: 1021. Disk full (/rdsdbdata/tmp/#sql_150_1.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")"

Weird cause when i check the databases and tables we just get 24gb used.. i increase 100gb and in 30 seconds was full too... then i config auto scaling storage top in 600gb, but the curious is after a 40 min the "full space" activity in the graph disappear.. i did not delete any log or temp (could not find the temp files). type => db.t3.large MariaDB version => 10.3.36 Storage type => General Purpose SSD (gp2)