Jetpack sharing – Shared Facebook text contains spam

My site was hacked recently, with extra text / code added to the header.php page.

I have corrected this as far as I am aware, but I still have one problem – the Jetpack sharing Facebook button still posts spam for most posts when sharing to Facebook. I am assuming this text is cached somewhere, but I have been unable to work out where.

A sample post: https://www.cyclingcartoons.com/the-cycle-race/ – clicking the Facebook button brings up text about payday loans and other such rubbish.

Any help much appreciated.

https://www.ads-software.com/extend/plugins/jetpack/