Can't Add custom property to Advanced search - SharePoint Online

Hi everybody, 

i just add a custom property on my advanced search WebPart on SharePoint Online.

First i linked a refinable property "RefinaleDate00" to my custom column (datetime). This column is a custom column on a specific doc library and it is not part of a content type.

Second, i edit the xml on the properties of the webpart "advanced search" and add the following lines : 

<ResultType DisplayName="Tous" Name="default">
<KeywordQuery/>
<PropertyRef Name="RefinableDate00" />

Then i tried to check if this new column appears and no .. nothing new on my search form. So i'm wondering if i did something wrong or if i need to wait a bit until a job or research crawl is activated ... Or if my custom colomns needs something specific to be able on search form ...

Thanks for your help !

Xavier.