Changed predis to phpredis: Getting segmentation fault - redis

Question

(Code is locally tested on a mac)
I've created a simple test for Redis, but it, unfortunately, fails with [1] 27996 segmentation fault:
// Config in App.php
// Had to rename Redis, because of the use of phpredis!
'RedisManager' => Illuminate\Support\Facades\Redis::class,
//Test unit
use Illuminate\Support\Facades\Redis;
/** #test */
public function it_can_set_a_dummy_value_in_redis()
{
$value = 'Hello';
Redis::set($this->cacheKey, $value, 'EX', 60);
$this->assertEquals($value, Redis::get($this->cacheKey));
}
It fails when the command set is fired.
I went through the code up to the point: Illuminate\Redis\Connections\PhpRedisConnection.php#command
I checked what the object-value of $this->client is:
Redis {#2278
isConnected: true
host: "127.0.0.1"
port: 6379
auth: null
mode: ATOMIC
dbNum: 0
timeout: 0.0
lastError: null
persistentId: null
options: {
TCP_KEEPALIVE: 0
READ_TIMEOUT: 0.0
COMPRESSION: NONE
SERIALIZER: NONE
PREFIX: "local_database_"
SCAN: NORETRY
}
}
I check the connection with:
dd($this->client->ping()); // it's true
However, it fails at the point:
return parent::command($method, $parameters); //set is called
Even though it is in a try-catch-block, it won't be shown there...
The logs show nothing:
nginx: 0 errors
php-fpm: 0 errors
redis:
2867:M 29 Aug 2020 22:46:03.142 * Background saving started by pid 27498
27498:C 29 Aug 2020 22:46:03.145 * DB saved on disk
2867:M 29 Aug 2020 22:46:03.306 * Background saving terminated with success
So even Redis is working correctly.
I don't know what is going on. When I change to predis, everything works fine!
The only hint I have got is this thread. But since my ping() is ponged, it should work?
Any ideas how I can fix my problem?