The problem appears when short URLs are using. And it is related to a wrong cached short URL inside the plugin. Easy Social Share Buttons for WordPress does not regenerate shorts on each page load – we do that once and cache it. The most common cause of the issue is generated short URL in a preview mode.
The avoid of generating short URLs in preview mode is an option added in version 5.6. For all new customers, it is ON by default from version 6.0. But if you import setup or you are a long time customer this option won’t be enabled.
In case of a problem with the Twitter URLs for sharing here are few things to check.
Enable the option to prevent the generation of the short URLs in preview mode.
This you can do in Advanced -> Advanced Options -> Short URL Issues.
Clear existing short URL cache.
This you can do from Import / Export / Reset -> Reset Settings & Data.
If you are running an older version of the plugin where you won’t see the reset feature. In this case visit again the Advanced -> Advanced Options -> Short URL Issues menu and temporarily enable the option Disable Short URL cache. The option will prevent plugin reading the already stored short and it will generate a fresh new when needed. After a few days, you can revert back its state to the default (NO).