I cannot see any related message which points to a Redis problem.
How do you know your problem is related to it?
Have you tried to use the array() syntax instead of using square brackets (I don’t know if it matters, but it is worse a try), like e.g.
YOUR SYNTAX: USUAL SYNTAX:
'redis' => [ redis' => array (
'host' => ... 'host' => ...
... ...
), ),
Have you checked the socket access rights of the Redis socket as described here:
Have you tried to access Redis using the network interface, like
'redis' => array (
'host' => 'localhost',
'port' => 6379,
'timeout' => 0.0,
),