Very useful, but the linkification limit doesn't work

I tried this plugin and it does what it says. However, as happened with another plugin doing the same job, the linkification limit doesn’t seem to work on my website. Indeed, even if I set the limit on in settings, all the occurrences of the same word within a single post get linked.

A s this is happening with the other plugin as well, I guess there might be some conflict with my theme or some other plugin I am using.