I seem to remember this worked perfectly, but also it seems not any more
I have unticked the box in preferences to display the age of a person for events happening after their death. Yet gramps still displays the dates. Which is clearly seen when entering a burial a couple of days after death. But it also does the same for dates much later. I have restarted, switched it on, restarted and switched it off again. I would like it to work again.
I am using AIO64-5.2.2 and the display age after death option is working as expected.
One thing to try, with Gramps closed, move or delete the gramps.ini file out of your user version directory. This will force a creation of a new .ini file.
The other thing, I am using this GrampsAIO-5.2.2-1_win64 file. Not sure what the differences in the builds may exist.