Spell Checker does not replace words

Hi everyone,

I’m trying to figure out how to solve an issue with LibreOffice Writer.
I have various spelling errors in a text (.odt file). I configured the Spell Checker properly, for the correct language. Incorrect words are underlined properly and the suggestions Writer makes are correct.

The problem:

Once I select one of the suggestions from the contextual menu (after right clicking a misspelled word), Writer INSERTS the correct word instead of REPLACING the incorrect one with the correct term.
e.g. This is a tset phrsae. → becomes “This is a testtset phrasephrsae.” instead of “This is a test phrase.”

I’m not sure what could be causing this. I considered the possibility of having to press the “Insert” key, because manually replacing words in Microsoft Word did require it, but it didn’t seem to make any difference here.

LibreOffice x64
Windows 10 Enterprise 1607

Is Edit>Track Changes>Record enabled?

It used to be Ctrl+Shift+C but it was dropped due to its too close similarity with Ctrl+C (Edit>Copy). If your document has not been edited for a while, this mode was perhaps enabled in a previous session and not cancelled.