On occasions, if you send your card to someone with an Apple divide, the Apple phone may block the download of the VCF file when shared via Facebook or LinkedIn.

This is because the in-app browser that Facebook and LinkedIn provide by default is very limited when compared with safari, firefox and chrome.

This is unfortunately out of our control, and have written a post about it below.

Sharing by SMS, email, and other methods will result in the devices default browser being opened, which will not be the in-app browser of Facebook or LinkedIn

See the full article