Seemingly Valid Phone number is throwing an error in deluge

Seemingly Valid Phone number is throwing an error in deluge

  1. {"code":"INVALID_DATA","details":{"expected_data_type":"phone","api_name":"Phone"},"message":"invalid data","status":"error"}
The above response is give when updating a contact with a valid UK phone number using deluge

When I manually add the same number into the CRM it gets added without any issues.

Any assistance on this would be appreciated