Impossible to display time values in the object list

Hi,

We're currently facing an issue,

When we're trying to add the column "estimated time" or "real time" in the ticket list, the column doesn't want to add itself, no errors or warning, it just doesnt work. Even with a lot of width space remaiming for the table ...

Is this normal as these values are stored on the "work - ticket" section of the customization plugin unlike the others ?

Thank you for your reply,

Regards