I found this documentation it very useful
https://www.c-rieger.de/losungen-fur-bekannte-nextcloud-18-fehler/
to set them to 1 min
*/1 * * * * php -f /var/www/nextcloud/occ documentserver:flush; php -f /var/www/nextcloud/cron.php > /dev/null 2>&1
I don’t know if there is already an official solution