Facebook Share button display on desktop but not on mobile

Dear sir/madam,

It is strange I can see the Facebook Share button on desktop view but not on mobile device. All Twitter, Google+, LinkedIn can display on mobile except Facebook.

I turn on the Web Inspect, I found the Width of Facebook div is 0 but normal on desktop?

Any idea I can fix the problem?

Best regards,

Kelvin.

https://wordpress.org/plugins/really-simple-facebook-twitter-share-buttons/