TLS not working on GKE+Istio even after LetsEncrypt issued the Certificates

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is: cjcabero.dev

I ran this command: kubectl -n istio-system describe certificate istio-gateway

It produced this output: https://i.stack.imgur.com/UOiKZ.png

My web server is (include version): Container Image ( paulbouwer/hello-kubernetes:1.8)

The operating system my web server runs on is (include version): Kubernetes v1.18.15-gke.1100 (debian)

My hosting provider, if applicable, is: N/A

I can login to a root shell on my machine (yes or no, or I don't know): N/A

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): N/A

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): N/A

For further details I also posted a question in Stackoverflow which can be found here -> https://stackoverflow.com/q/66243262/2475170