Why does it not work to call a phone number stored in a card?

Eureka! GreyM1P you suggest me the solution: no spaces or any other symbols should be included.
But I would like to point out that this problem did not exist in previous versions of 1P: I had many phone numbers stored with spaces and they still worked.
I only detected it a few months ago (and my 1P is always updated to the latest version!).
Thank you very much