Bash is the shell I use over SSH.  
It's interesting that your QSH gives an error on the -h flag.  I would have thought it would be the same regardless of what shell you have set.  Are you on 7.3?  Running du without the -h flag gives me all the results in KB, without a label.
FYI, some info on shells:
http://ibmsystemsmag.com/blogs/open-your-i/august-2017/tech-tip-be-like-a-turtle/
-----Original Message-----
From: Alan Shore [mailto:ashore@xxxxxxxx] 
Sent: Wednesday, January 09, 2019 8:13 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: RE: How to obtain size of ifs directories and sub-directories
Thanks for the reply Justin
I tried this command in STRQSH and received the reply 
/QOpenSys/usr/bin/du: Not a recognized flag: h       
 Usage: du [-a | -s] [-rlkmgx] [ -H | -L ] [Name ...] 
 $                                                    
AND
This is where I show my ignorance
What is bash?
Alan Shore
E-mail : ASHORE@xxxxxxxx
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