Facetime issue with specific contacts on iPad

Hi,

With my iPad I can facetime with almost of my contacts except with two people. When I type their name I can see only the phone logo, not the video camera logo. Same when I scoll down all the names in my contacts. Those two only have a phone logo beside their phone number, all others have the video camera logo. Yes, Facetime is turned on on their computers. I'm grateful for any help.

Willi

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