Hi ETH devs, is there anyone knowledgeable about linked accounts and permissions?

I possess an Ethereum address containing funds and private keys. However, I am encountering difficulties sending ETH from the wallet due to an error stating "signature does not match."

The mentioned address is also linked as a "smart address" to another address, presumably for control permissions. I have the private keys for both addresses but am unsure of the necessary steps to resolve the issue.

If you have expertise in addressing this matter, please PM