No sentinel server available for autodiscovery

Hi

After updating to version 2.1.6, the following error is occurring.
(There was no problem at all until the previous version)

WARNING: [pool www] child 721552 said into stderr: "NOTICE: PHP message: Predis\ClientException: No sentinel server available for autodiscovery. in ...wp-content/plugins/redis-cache/dependencies/predis/predis/src/Connection/Replication/SentinelReplication.php:286"
WARNING: [pool www] child 721552 said into stderr: "Stack trace:"
WARNING: [pool www] child 721552 said into stderr: "#0 ...wp-content/plugins/redis-cache/dependencies/predis/predis/src/Connection/Replication/SentinelReplication.php(474): Predis\Connection\Replication\SentinelReplication->getSentinelConnection()"
WARNING: [pool www] child 721552 said into stderr: "#1 ...wp-content/plugins/redis-cache/dependencies/predis/predis/src/Connection/Replication/SentinelReplication.php(499): Predis\Connection\Replication\SentinelReplication->getSlaves()"
WARNING: [pool www] child 721552 said into stderr: "#2 ...wp-content/plugins/redis-cache/dependencies/predis/predis/src/Connection/Replication/SentinelReplication.php(660): Predis\Connection\Replication\SentinelReplication->pickSlave()"
WARNING: [pool www] child 721552 said into stderr: "#3 ...wp-content/plugins/redis-cache/dependencies/predis/predis/src/Client.php(220): Predis\Connection\Replication\SentinelReplication->connect()"
WARNING: [pool www] child 721552 said into stderr: "#4 ...w..."

My redis environment is sentinel .
It is the environment I have been using and there is no problem with redis at all.