Unable to Sign Transactions with Nested Proxy Accounts

[asiniscalchi]

• I'm submitting a ...
  Bug report

• What is the current behavior and expected behavior?

When trying to send tokens from a nested proxy account (proxy_1 controlled by proxy_0), the application displays an error: "Cannot sign with a locked key pair." The expected behavior is that Polkadot.js should be able to sign transactions with nested proxy accounts without any issues.

• What is the motivation for changing the behavior?

This issue prevents the use of nested proxy accounts for transactions, limiting the flexibility and security provided by hierarchical account structures. Fixing this bug would allow users to fully utilize nested proxy accounts.

• Please tell us about your environment:

  • Version: v0.137.2-41
  • Environment: Browser (Chrome/Firefox)

• Screenshots to illustrate the issue:

• Steps to reproduce:
  1. Create a pure proxy account controlled by Alice (proxy_0).
  2. Create another pure proxy account controlled by proxy_0 (proxy_1).
  3. Attempt to send tokens from proxy_1 to another account.
  4. Observe the error message: "Cannot sign with a locked key pair."

Thank you for your attention to this issue.