codesign fails with errSecInternalComponent

Hello, I am trying to sign my application with my developer id, but codesign always fails with error errSecInternalComponent.

I found similar issues on the internet, where the solution was to lock the keychain, then running codesign so it ask for the password to unlock the keychain, but that didn't work for me.

So here's what I do:

1. go to KeyChain app and File -> Lock all keychains
2. in Terminal: codesign --force --deep --sign "Apple Development: my name (alphanumeric id)" MyApp.app but it errors:

Warning: unable to build chain to self-signed root for signer "Apple Development: my name (alphanumeric id)"

MyApp.app: errSecInternalComponent

A few basic checks:

developer certificate is installed:

In XCode -> Preferences -> Accounts I have my apple ID with the developer subscription, and if I click Manage Certificates I see one cert under "Apple Development Certificates" I created today.

Is it the correct type of certificate to sign apps?

How can I fix my problem?