To configure a YubiKey's NDEF setting, which controls which OTP slot it will use over NFC, follow the steps below. This is necessary because controlling which slot is used via short or long touch is not possible when connecting via NFC.

Using YubiKey Manager (CLI)

1. Follow the instructions on here to install YubiKey Manager (CLI) and get it working in your command-line interpreter (Terminal, PowerShell, etc.)
2. Run ykman otp ndef {1|2}, where {1|2} is 1 or 2, depending on which slot you want your YubiKey to use over NFC. By default, the YubiKey is programmed use OTP slot 1 over NFC.