ACS 1.1.8.5 system debugger "Unknown system 'Myibmi' was specified"

I'm running ACS 1.1.8.5 on a Win10 system.  I connect to a v5r4 system, click on Run SQL Scripts, which starts fine.  I'm able to run a simple SQL to verify that I am indeed connected, then I go to the Run menu, click on System Debugger, and it opens the debugger window.

At the top of the debugger window, it shows the job and system I'm connected to, as well as my user id.  After a few seconds, with me doing nothing, a Error window pops up saying "Unknown system 'Myibmi' was specified."  That's the same system name that's at the top of the System Debugger window, where it was apparently able to connect to a QZDASOINIT job with no problem. And that job is running. Its joblog shows

 Job 131393/QUSER/QZDASOINIT started on 10/04/21 at 09:17:46 in subsystem
   QUSRWRK in QSYS. Job entered system on 10/04/21 at 09:17:46.
 ACGDTA for 131393/QUSER/QZDASOINIT not journaled; reason 1.
 ACGDTA for 131393/QUSER/QZDASOINIT not journaled; reason 1.
 User PDOW from client 10.106.35.120 connected to server.
 ACGDTA for 131393/QUSER/QZDASOINIT not journaled; reason 1.
 Library QGPL already exists in library list.
 Library PDOW already exists in library list.
 SET_MONITOR_OPTION in QSYS2 type *N not found.
 SET_MONITOR_OPTION in QSYS2 type *N not found.
 RETURN_VARIABLE_VALUES in QSYS2 type *N not found.

The job start message shows 10/04/2021, but all the other messages are from today, 10/06/2021.

On the IBM i, I used STRDBGSVR, then tried again.  Didn't help.

I tried connecting to a v7r3 system, but got the same error.

What am I missing?

--
*Peter Dow* /
Dow Software Services, Inc.
909 793-9050
petercdow@xxxxxxxxx
pdow@xxxxxxxxxxxxxx /