custom links are not linking to the post

Hi there,

we have the pro version: 1.8.7

our custom links were working before. However, only one page got randomly added the smart link now:
https://www.calliduscloud.com/blog/thunderbridge/start-analyzing-now-predict-the-future-tomorrow/
no setting changes in the plugin and it was stop working about a month ago.

any insides or any direction that could point us to do further investigation will be appreciated!

Thanks.
Heng

https://www.ads-software.com/plugins/seo-automatic-links/