I cannot reproduce this, steps I tried:
1) Select two books with some value a custom date column
2) Click edit metadata
3) Set the date column to today
4) Click OK
5) Press F2 to edit one the changed dates
6) The date shown in the edit box is today's date
Unfortunately I cannot see your video, since the domain it is hosted on is blackholed in my DNS server. Make sure you are not pressing the Ctrl key at the same time as F2, that will cause the date editor tobe initialized to a fixed value.
I also looked at the code and I cant see how it is possible for it to get the previous value, but, the code was awkward, so I have simplified it
https://github.com/kovidgoyal/calibr...250007a957814e