Date formatted differently for specific values in a table

Hi all, 

I have a problem in the date format on Power BI Service. This problem is happening only for some dates. 

Sometimes the date format are inverted. 

My PBI are linked to a SP Liste as a datasource. 

Here's the value i have in the datasource :

Why the format is changing for specific values ? 

Many thanks for your help. 

best regards,