Microsoft Advertising has two targeting options that are somewhat similar, but operate differently:
The language targeting option might cause issues, as it is not explicitly stated to be a geography target and there’s no way to edit once an ad group is set. The platform does offer a way to select this setting upon creation, however it is only available through the application interface, not a bulk sheet. This would force you to create each ad group one at a time, which is not scalable.
The below process can be followed to ensure accurate language targeting in both the Platform and Microsoft Ads: