Pruning isn’t working anymore on 27.1.0

My state of affairs

du -sh .bitcoin/
14G .bitcoin/

I’ve allow 6G for pruning

bitcoin-qt -prune=6000

I wait..nonetheless 14G

du -sh .bitcoin/
14G .bitcoin/

I shut bitcoin and.. 14G

I edit .bitcoin/bitcoin.conf

prune=6000

I restart bitcoin-qt and nonetheless 14G occupied house
Why?

System is: Slackware 15.0
Bitcoin model is : 27.1.0