Herkou Redis - certificate verify failed (self signed certificate in certificate chain)

I have been using heroku redis for a while now on one of my side projects. I currently use it for 3 things

1. It serves as a place for me to store firebase certificates
2. It is used for caching data on the site
3. It is used for rails sidekiq jobs

Recently, my heroku usage went up and I had to change it to use heroku redis premium plan. Ever since then I have been getting error: SSL_connect returned=1 errno=0 state=error: certificate verify failed (self signed certificate in certificate chain) somehow. Everything stayed the same yet the error started popping out of nowhere.

Does heroku-redis premium plan work fundamentally different than a basic heroku-redis plan?

I am using ruby on rails, deployed on heroku with heroku redis if that helps.