In the Editor, typing a select statement that has an alias for a table, and adding a column to in the SELECT section of the statement, when one type the alias and a dot a list of the available columns is listed, but it's long so one have to add a letter to filter it, but, instead of filtering it Toad clears out the list, it shows no columns at all when adding a letter to filter it, for example, this is how it looks when adding just the dot:
And This is how it looks when adding a letter: