How to fix the error Code: 40318 on the Microsoft 365 developer Program Sandbox Creation?

Question

Hi All,

I'm getting the below error, when attempting to Add phone number for security, in the MS 365 developer program Sandbox creation.
Even tough my phone number is correctly formatted, it's active and I'm using it currently.

Country code: Curacao (+599)
Phone number: 96xxxxxx

x = digit number

I added an x to reflect an actual digit (for privacy purposes)
Although in the security section I used a real digit(real number).

Error received:
We can't continue with the signup process for the following reason:

• Your phone number is not formatted correctly. Please verify your number and try again.

MS-CorrelationId: 00000000-b514-47aa-b7a4-21dcd61921d9

Code: 40318

Your help will be appreciated, as I'm trying to follow the MS-900 course.