The increasing interconnectedness of devices via the Internet of Things (IoT) highlights the growing importance of addressing IoT security issues. Authenticated Key Agreement (AKA) protocols ensure secure communication between IoT devices, users, and central servers. Preserving anonymity in AKA protocols is especially crucial given privacy issues and user preferences. The emergence of Shor's algorithm in 1994 and recent advancements in quantum computing have posed a threat to the security of classical AKA schemes relying on integer factorization, discrete logarithm, and other number theory problems. Consequently, researchers have turned their attention to developing quantum-resistant AKA schemes. In this context, Rana and Mishra introduced a lattice-based key agreement protocol under ring-LWE problem for IoT-enabled smart devices. However, a thorough security assessment uncovered vulnerabilities in their protocol, specifically susceptibility to replay and Key Compromise Impersonation (KCI) attacks. Furthermore, their approach reveals potential weaknesses in user impersonation if the user's identity is compromised.