Number not recognised?

Hi
I am trying to call an elderly relative on a Lebara phone but I just get the number is not recognised.

I am the account owner and there's nothing on the account to suggest there's a problem. But I have no other way of contacting the relative.

Any ideas? Is there a problem on the network right now that would cause a problem?

Just checked network status in the area and looks like there's 4g and 5g problems.... Could this cause "number not recognised?"