Database manager error

Hi.
I work around a dynamic site with php server model and mysql db, when i try a db connection with database manager is impossible because return ETIMEDOUT error and no load db schema. If i make a connection by server Connect work fine… i can create a query with query builder but when i try to insert my dynamic data on the page, in the select window don’t display any query and any field from db. I have make some projects from begin, i have reset my current project, i unistalled Wappler and reconfigurate all… always same problem. How i can resolve?