Problem: I've generated a key with a passphrase but the passphrase is not requested when connecting.
Termius supports RSA, DSA, ECDSA, and ed25519 keys for passwordless login. When generating your key you may protect that key with a passphrase. The private key will be encrypted using an extra layer of security. Termius stores the passphrase together with the key's other values in the keychain, so you won't be prompted for the passphrase upon connection.
If you'd rather Termius not store the passphrase, just remove the passphrase from the key's settings in the keychain by navigating to the specific key and removing the value in the Passphrase field.