Sidekiq Stuck in Idle Mode (Heroku)

I'm having a problem with my Rails server that's running in production on Heroku. Just recently, my Sidekiq jobs have stopped processing, and Sidekiq seems to be stuck in some sort of 'idle' state:

I've been running around on the internet all morning, but I can't seem to find any good resources for debugging this. If someone can point me in the right direction, I would really appreciate it.

Relevant Versioning:

Ruby    '2.5.8'Rails   '5.2.4.4'Sidekiq '6.1.2'Redis   '4.2.0'

Relevant Config Vars:

REDIS_PROVIDER=REDISTOGO_URLREDISTOGO_URL=redis://redistogo:[secret]@crestfish.redistogo.com:11137/REDIS_URL=redis://redistogo:[secret]@crestfish.redistogo.com:11137/

Sidekiq.yml

:concurrency: 5staging:  :concurrency: 10production:  :concurrency: 10:queues:  - [default, 1]

initializers/sidekiq.rb

Sidekiq.configure_client do |config|  config.redis = { url: ENV["REDIS_URL"] }end

initializers/redis.rb

REDIS = Redis.new(uri: URI.parse(ENV["REDIS_URL"] || "redis://localhost:6379/"))

Any help would be greatly appreciated. Thank you!