from https://www.linuxuprising.com/2019/07/how-to-completely-disable-tracker.html

Disable
  systemctl --user mask tracker-store.service tracker-miner-fs.service \
     tracker-miner-rss.service tracker-extract.service \
     tracker-miner-apps.service tracker-writeback.service
  tracker reset --hard

Check with 
  tracker status
  tracker daemon
  
Enable again 
  systemctl --user unmask tracker-store.service tracker-miner-fs.service \
     tracker-miner-rss.service tracker-extract.service 
     tracker-miner-apps.service tracker-writeback.service