OK, done. I don’t see any errors in debug.log:
PHP Notice: wp-ffpc init starting in /path/to/wp-content/plugins/wp-ffpc/wp-common/wp-plugin-utilities.php on line 59, referer: https://domain.tld/
PHP Notice: wp-ffpc 127.0.0.1:11211 added, persistent mode: 0 in /path/to/wp-content/plugins/wp-ffpc/wp-common/wp-plugin-utilities.php on line 59, referer: https://domain.tld/
PHP Notice: wp-ffpc checking server statuses in /path/to/wp-content/plugins/wp-ffpc/wp-common/wp-plugin-utilities.php on line 59, referer: https://domain.tld/
PHP Notice: wp-ffpc 127.0.0.1:11211 server is up & running in /path/to/wp-content/plugins/wp-ffpc/wp-common/wp-plugin-utilities.php on line 59, referer: https://domain.tld/
PHP Notice: wp-ffpc CRON clearing event in /path/to/wp-content/plugins/wp-ffpc/wp-common/wp-plugin-utilities.php on line 59, referer: https://domain.tld/