Sharing adds an @

Could you try to disconnect and reconnect Twitter’s Publicize connection, by following the instructions here:
https://jetpack.me/support/publicize/twitter/#reconnecting-twitter

Once you’ve done so, can you try publishing a new post and let me know if it helped?

I have followed the steps and will report back after the next post goes up

Hi,
I have followed those steps and tested with the next post with the same results

Thanks. I ran a few more tests on my end, and managed to find a way to fix things.

Could you try to apply the changes highlighted here, and let me know how it goes?
https://github.com/Automattic/jetpack/pull/1207/files