The integration of 6G and Time-Sensitive Networking (TSN) is desired to provide both mobility and deterministic communication. In TSN, Frame Replication and Elimination for Reliability (FRER) improves stream resilience using redundant paths. However, the original FRER with a fixed history length is ineffective when facing variable-delay links that cause reordering and bursty arrivals of packets. We propose the Dynamic History Length (DHL) algorithm that dynamically adjusts the FRER elimination buffer based on real-time link delay measurements. We implement and evaluate DHL in OMNeT++/INET, which provides a comprehensive and high-accuracy model of TSN switches. We compare DHL with the FRER variations. In a 100 ms dual-link simulation with latency ramps and a 10 ms outage, DHL reduces duplicate packet deliveries by 39 % compared to baseline. In terms of the 99th percentile inter-arrival intervals, DHL shows an improvement of 4.3 ms compared to the sorting and shaping algorithm, allowing it to better match the sender's 1 ms transmission interval.