Word/character count in LO 5

Hi. The word and character count doesn’t work properly when I open a large document in Writer. It counts approx. 1/10 of the words/characters and then stops, adds then approx. 5,000 after a keystroke until it reaches the correct amount. The correct amount is only displayed after clicking Tools/Word count. This doesn’t apply to small documents. My document has approx. 140,000 words and just over 1,000,000 characters.

Word count in task bar.