signing failed for RSA from agent: agent refused operation

I've seen this discussion on the same subject but I'm not sure what the current status is.

I've added my existing SSH key to 1Password following the instructions. My key was generated as an RSA 4096. It has a passphrase and I've entered that into 1Password when importing.

I've enabled and configured the SSH Agent in 1Password (Screenshot). I've also added the following to ~/.ssh/config`:

Host *
  IdentityAgent "~/Library/Group Containers/2BUA8C4S2C.com.1password/t/agent.sock"

I've previously had my SSH key added to my GitHub account (and working with it regularly). When I attempt a connection to GitHub to test the 1Password agent integration I'm met with an error following Touch ID authentication:

sign_and_send_pubkey: signing failed for RSA "/Users/ian/.ssh/id_rsa" from agent: agent refused operation
git@github.com: Permission denied (publickey).

I've created a 10 second screencast demonstrating the flow and error.

I'm on an Apple M1 Pro running Ventura 13.0 and 1Password for Mac 8.10.4 (81004032) (current latest).

Can someone advise as to what the problem could be and how I can resolve it?

1Password Version: 8.10.4
Extension Version: Not Provided
OS Version: macOS 13.0
Browser:_ Not Provided
Referrer: forum-search:Do I still need to keep my SSH key in ~/.ssh/ ?