Wrong result when applying aggregation function on series with * and where clause

There is an error with the result of aggregation on series with * and where clause.

Data:

Select result:

The value of count(root.ln.wf02.wt02.temperature) should be 21 but it turned out to be 5 according to result of the `select count(temperature) from root.ln.*.* where temperature > 50.0`. The error also happened with regard to the `avg` function.