When the next statement is a variable declaration, autocomplete on the previous statement seems to be generated from the surrounding class context instead of the correct object. It is probably easiest to explain with a screenshot:

In this example, I expect to see proposals for the String and GString types, but actually observed behavior is I see proposals for the surrounding class (CompletionProblem).

If instead I change the code to instead use a different statement (eg: assignment) then I see the correct autocomplete proposals: