Another quick update.
I also re-flashed one of the other 4K-T's I have using IE (again following the steps I shared), then went into Safari and setup new config, changing settings etc and configuring schedules as well. I saw the schedules change correctly on each time interval I set them to on the Time Plan and saw this reflected in Live Mode as well as in Camera menu (preview screen) + also on Mobile (iDMSS) connecting to the camera too. I then repeated this exact using Firefox (both of these browsers on Mac for this test) and again successfully saw schedules change at the right time in Live & Camera views + settings did not shift or get reset.
Just making sure I kept all up to date. As mentioned above this is definitely appearing to potentially be browser related (for those seeing the issue) both in terms of initial upgrade (DO NOT USE EDGE) and potentially for the settings piece (will continue to monitor for this overnight). So to recap, I've tested on IE (PC) + Safari & Firefox on Mac, all switch the schedules when expected and retain settings. Edge is 100% a no go and as mentioned above, if you did initially upgrade via Edge (heck even if you didn't and the cam arrived with 9/26 and you see issues), then I would advise to follow the multiple FULL factory default steps I mentioned in IE, re-flash the cam using IE, setup and configure in IE for test. You could even upgrade using IE and then test in another browser if you wish (just NOT EDGE).
As I went to post this, I just re-tested the above 1 more time on the 3rd 4K-T just for sanity check, that worked too