There is an error in function TDAEDOAConnection.CreateCompatibleQuery. Currently the code of this function calls again OracleSession.LogOn this forces the connection to close the current session and login again into Oracle. This creates a problem for pending commits and some queries thad depend on current Oracle session like queries that ask for current sequence values.
The correct code for this function should be:
function TDAEDOAConnection.CreateCompatibleQuery: IDAServerDataset; begin Result := inherited CreateCompatibleQuery; end;