I noticed an anomaly after I upgraded the firmware, reset the router, performed the Quick Internet Setup and then performed my configuration settings.
When I went to the Administration > System to set the "DST time zone changes ends" for Central Time zone to the correct month & day, I saw a message on the Time Zone that "System time zone is different from your locale setting".
The Time Zone setting which by default was correctly showing Central Time (US, Canada) in the GUI and I did not have to change the locale time zone however the system time zone was not set correctly during the Quick Internet Setup.
I never had this problem in the past when I performed the steps listed at the top of this post.
In the GUI, I reselected the Time Zone as Central Time (US, Canada), made the DST change, clicked the Apply button and via the GUI rebooted the router to resolve the problem.
I reported both the incorrect "DST time zone changes ends" and the locale Time Zone not set correctly to the local setting during Quick Internet Setup to ASUS via the router's feedback option.