The Redis client returns the redis: nil error

I am writing a client wrapper Redis for caching data downloaded from online services:

import (
    "github.com/go-redis/redis/v7"
)

type Cache struct {
    client *redis.Client
}

// Инициализация из примера в документации
func NewRedisClient() *redis.Client {
    return redis.NewClient(&redis.Options{
        Addr:     "localhost:6379",
        Password: "", // no password set
        DB:       0,  // use default DB
    })
}    

func NewAudioCache() *Cache {
    ret := &Cache{client: service.NewRedisClient()}
    // ret.client.HSet("test", ExclKey, "C")
    // log.Println(ret.client.HGetAll("test").Result())
    return ret
}

func (c *Cache) ExclusionsByProcessor(processor common.ProcessorType) ([]string, error) {
    res, err := c.client.HGet(ExclKey, processor.String()).Result()
    if err != nil {
        return nil, err
    }
    return strings.Split(res, ","), nil
}

On a host with golang 1.12/SparkyLinux, calling wrapper methods works correctly, and on golang 1.13/ArchLinux, it throws an error redis: nil in ExclusionsByProcessor() and other methods.

Ping() works everywhere. The commented out code in NewAudioCache() also works.