Sidekiq 7 / Redis-client not working (on Heroku)

I am using Sidekiq on an app hosted on Heroku.
I have been using the redis gem.

Now I am trying to upgrade to sidekiq 7 which uses redis-client instead of redis. And when doing so I get this error:

redis-client requires Redis 6+ with HELLO command available

The Redis instance I have on Heroku is on the version 6.2.6 (so Redis 6+) (picture attached)

Below my redis.rb file (which is in initializers). I replaced Redis with RedisClient but I still get the error in both cases (in the case where I use the redis gem with Sidekiq 7 and the case where I use redis-client).
It means that it is when the Sidekiq inner code is using redis-client that the error is happening.

Any thoughts or ideas would be highly appreciated 🙏🏼 Thanks in advance!

I was expecting this to work as my Redis instance is on a 6+ version

url = ENV["REDISCLOUD_URL"]

if url
  Sidekiq.configure_server do |config|
    config.redis = { url: url }
  end

  Sidekiq.configure_client do |config|
    config.redis = { url: url }
  end
end