Process Instance log 'Sub Process' filter not matching expected entries

'Sub Process' checkbox for filtering logs of a process instance based on Event Node Type is not working properly.

For a process with subprocesses, the 'All' filter returns several log entries for subprocesses like:

SubProcessNode 'sub2' (System) node was ENTERED 

But when I check only the 'Sub Process' checkbox, no log entries are returned at all.