I did as you asked—see attached for the settings. Does it bother you that the "How should data be retrieve...." field appears unset? I set it, click Save and when I come back later, the "How should data be retrieve...." field again appears unset. Is that normal?
After that things get strange.
I already had a tail -f running for the plugin log file, and when I looked at that terminal window (before repeating the steps as you asked) I saw
home:com.karlwachs.INDIGOplotD home$ tail -f plugin.log
08:56:21 theCol:1; updatesALL:True; sqlDynamic:batch-resetTo-batch2Days; sqlHistListStatus:[0, 50]
08:56:21 Convert no records found, try later 1
08:56:21 Convert no records found, try later 2
08:56:21 redolineDataSource called from : cleanData
08:56:21 redolineDataSource: listOfSelectedDataColumnsAndDevPropName[(0, 'None'), (1, u'SI_CR_Door')] calledfrom :cleanData
08:56:21 clearSqlData sqlupdates: [0, 0]
08:56:21 SQL imp. 2020-08-04 08:56:21.161700 ... sqlColListStatus: [0, 0]
2020-08-04 08:56:22.926 ERROR Plugin.checkSQLdata Line '9284' has error='None'
08:56:22 matplot stopped PID: 47774
08:56:22 main loop stopped
Note that the log files is in /Users/home/Documents/Perceptive Automation/Indigo 7.4/Logs/com.karlwachs.INDIGOplotD/plugin.log (under my Documents folder) because I have Indigo running from there, so my Indigo files are backed up by Backblaze.
Anyway, with the tail -f still going, I repeated the steps as you asked, but I never saw anything new written to plugin.log, and the device was not added. I tried several times.
I decided to try and reload the plugin, and in the Indigo log I saw
Reloading plugin "INDIGOplotD 7.20.71"
Stopping plugin "INDIGOplotD 7.20.71" (pid 48028)
Stopped plugin "INDIGOplotD 7.20.71"
Starting plugin "INDIGOplotD 7.20.71" (pid 73932)
INDIGOplotD initializing ...
INDIGOplotD path To files: =================
INDIGOplotD indigo /Library/Application Support/Perceptive Automation/
INDIGOplotD installFolder /Library/Application Support/Perceptive Automation/Indigo 7.4/
INDIGOplotD plugin.py /Users/home/Documents/Perceptive Automation/Indigo 7.4/Plugins/INDIGOplotD.indigoPlugin/Contents/Server Plugin/
INDIGOplotD Plugin params /Library/Application Support/Perceptive Automation/Indigo 7.4/Preferences/Plugins/com.karlwachs.INDIGOplotD/
INDIGOplotD (testing logger; see >/Library/Application Support/Perceptive Automation/Indigo 7.4/Logs/com.karlwachs.INDIGOplotD/plugin.log< for detailed logging
INDIGOplotD Error !!!!INFO ONLY!!!! logger enabled for ERROR !!!!INFO ONLY!!!!
INDIGOplotD Critical Error !!!!INFO ONLY!!!! logger enabled for CRITICAL !!!!INFO ONLY!!!!
INDIGOplotD check /Library/Application Support/Perceptive Automation/Indigo 7.4/Logs/com.karlwachs.INDIGOplotD/plugin.log <<<< for detailed logging
INDIGOplotD Plugin short Name INDIGOplotD
INDIGOplotD my PID 73932
INDIGOplotD set params 4 indigo V 7.4
Started plugin "INDIGOplotD 7.20.71"
INDIGOplotD initializing ... ; debuglevel=['General', 'SQL']
INDIGOplotD number of days per bin category are: [8, 38, 390] for [days, hours, minutes] data
INDIGOplotD using '/usr/bin/python2.7' for utily programs
INDIGOplotD testing if variable enableTimeTracking_INDIGOplotD is == on/off/print-option to enable/end/print time tracking of all functions and methods (option:'',calls,cumtime,pcalls,time)
INDIGOplotD SQLMode: ; GNUPLOT/MATPLOT: mat; GNUplotVersion= ; PLOT-Directory= /Library/Application Support/Perceptive Automation/Indigo 7.4/Preferences/Plugins/com.karlwachs.INDIGOplotD/
INDIGOplotD Error self.timeDataNumbers wrong number of columns: 2/1trying to fix
INDIGOplotD Error self.timeDataNumbers wrong number of columns: 2/2trying to fix
INDIGOplotD checking py-restore files
Note the "wrong number of columns" Error messages near the end.
After that I was surprised that I was then able to add four devices using the steps I posted previously, and then...the fifth did not work, nor the next, etc. I was unable to add any more.
I still never saw any changes written to plugin.log — the last entry is the "main loop stopped" — which is from BEFORE I was able to successfully add the four devices.
I can try and wipe everything out and start over if you think best—in fact I tried to do that but it didn't seem to help. If you think that's worth trying again, please let me know which things I need to delete, steps to take, etc. to completely start over, and I will try.
Thank you for the help!