Redis as session driver

Got a weird problem when trying to use Redis as the session driver. Using tinker I'm able to query the Redis server and set keys etc. But when I try to access from the web (using sessions) I get the following:

FatalThrowableError in RedisStore.php line 54:
Fatal error: Call to a member function get() on null

in RedisStore.php line 54
at RedisStore->get('45935b607e4b58923f504d210f85454aba5e23c4') in Repository.php line 129
at Repository->get('45935b607e4b58923f504d210f85454aba5e23c4', '') in CacheBasedSessionHandler.php line 58
at CacheBasedSessionHandler->read('45935b607e4b58923f504d210f85454aba5e23c4') in Store.php line 124
at Store->readFromHandler() in Store.php line 108
at Store->loadSession() in Store.php line 92
at Store->start() in StartSession.php line 104
at StartSession->startSession(object(Request)) in StartSession.php line 57
at StartSession->handle(object(Request), object(Closure))
at call_user_func_array(array(object(StartSession), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing{closure}(object(Request)) in AddQueuedCookiesToResponse.php line 37
at AddQueuedCookiesToResponse->handle(object(Request), object(Closure))
at call_user_func_array(array(object(AddQueuedCookiesToResponse), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing{closure}(object(Request)) in EncryptCookies.php line 59
at EncryptCookies->handle(object(Request), object(Closure))
at call_user_func_array(array(object(EncryptCookies), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 136
at Pipeline->Illuminate\Pipeline{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Kernel.php line 132
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
at Kernel->handle(object(Request)) in index.php line 53

Config: config/cache.php (stock standard):

        'redis' => [
            'driver' => 'redis',
            'connection' => 'default',
        ],

config/database.php:

'redis' => [
        'cluster' => false,
        'default' => [
            'host'     => env('CACHE_HOST','127.0.0.1'),
            'port'     => 6379,
            'database' => 0,
        ],
    ],

config/session.php:

<?php
return [
    'driver' => 'redis',
];

If it makes a difference I'm using an external Redis server. Telnet is successful.

Cheers