Double password prompt when unlocking 1Password on macOS

Hello et all,
I am experiencing some strange behavior on my Mac that I haven't been able to resolve.

Every time I try to autofill a password, the 1Password dialog appears as expected. I enter my password to unlock the vault, but immediately after 1Password unlocks, a second macOS system window (which appears to be the native Keychain/System prompt) pops up and asks for my password again.

I am essentially being asked to authenticate twice for a single login action. I have attached a screenshot of the second prompt for reference: https://drops.tdv.ngo/JPrLjwJH

Could you please help me understand why this is happening and how I can stop this double-prompting?

best wishes,
/a.