Split words spelling mistake

The LanguageTool LibreOffice plugin (and standalone software) doesn’t correctly catch and correct split words spelling mistakes. For example, when checking the following excerpt five possibly wrong words are identified (i.e. conun, defi, nition, unea and, sily), when actually there are three:

“The conun drum of Norton’s defi nition partly has to do with how unea sily biodiversity straddles the worlds of nature and human projects”.

Yet, the https://languagetool.org/ website is able to correctly remove spaces in split words (except for conun drum).

Is it meant to be that way? Is this kind of correction a premium feature? Or am I doing something wrong?

I am using LibreOffice 6.4.6.2, and LanguageTool 5.0.1. Using n-gram and neural network correction doesn’t solve the problem.