You didn’t indicate if the library where PHF1 and LF1 are is in your library list when you issued the STRSQL command. If it is in the library list then try naming the library on the select command:
Select * from specific_library/LF1
You can also issue the STRDBG command without any other parameters. Then issue STRSQL, run your select statement and then review the job log for your job. Doing this will generate a trace of what SQL is up to and it might help pinpoint the problem.
Hope this helps…