I am using Studio 2021 by the way, and I checked the settings in Options, auto-substitution.

Can you provide more details? What are you expecting to see? What actually happens? A screenshot would be very helpful. 

Hi Nora, thanks for your reply. In the dropdown list that appears after ctrl + comma, I used to have the full date, in this case '10 juillet 2020'. Also, as you can see in the source segment, the full dates are not marked with a blue line, so they are not considered as placeables. Only the individual numbers are considered as placeables.

and this is what my current settings look like

and this is what my current settings look like