...

First of all, do not hesitate to contact the XTM Support team so that they can confirm that the problem is related to API endpoints indeed.
Microsoft MT has different API endpoints for different regions. If an your API endpoint is not a default endpoint, the XTM International Support team needs to add it so you can specify an API custom endpoint (whose name includes the region for which it has been selected).
You then need to sign in to your Microsoft MT integration portal, and find both the key and the region you are using. For example:

...

Info
If you are unsure where to type it in, provide the XTM Support team with a screenshot or information from the integration portal that shows a location/region and an endpoint (as presented on the first screenshot).

OPTIONALLY

...

You can specify

...

a MS MT engine per XTM Cloud customer. To do so:

Select Customers → Customer list → (select a customer) → Settings → Machine translation.
From the Microsoft Translator login data dropdown, select Customer specific.

Image Modified

You will now be able to enter a different API key from the one defined in the global settings.

...

Different API endpoints in Microsoft MT

...

Versions Compared