@davidjpalmer71: Sorry to hear that your Eye Comfort Shield isn't turning off as scheduled. As a workaround, please swipe from the top of the screen to the bottom, then again to enlarge the Quick Panel > Press and hold on the Eye Comfort Shield icon > Custom > Set Schedule > Custom, and manually set the time you'd like the feature to turn on and off.
I turn on my Galaxy Tab S6 each morning after sunrise. Sometimes the eye comfort shield turns off after a few minutes but usually I have to turn it off manually.
Still unfixed... Wow