My database is all ways deleted after two or 3 days

Hello every body, i'm an administrator of a website witch use a Dedicated Server, i have a problem with it: I have one database called: 'myusernam_database1' and sometime to make test to know if it work well, i copy the 'myusernam_database1' to 'test' for just test, after test i dont delete the 'test' database but after two or more days when i log to my WHM again, i can not see it, i try it 4 times and it deleted itself. Is there someone to help me to know how the 'test' database it delete itself? NOTE: 1/ When i do that, i use the WHM Phpmyadmin, i dont log to cpanel. 2/ "Require a username prefix on names of new databases and database users