Text messages to Apple Card Support are not delivered.

In the Wallet app on my iPhone, if I go to my Apple Card, tap the three dots in a circle, select Card Details, and tap the Message button, I should be able to send a question to Apple Card Support. All day today, though, the resulting text message comes back with a "Not Delivered" error.

It seems unlikely Apple Card Support has been off the air all day. I've tried rebooting my iPhone--no difference. Text messages to other recipients work fine.

Is anybody else seeing this?