No — when you rebook any segment of your itinerary (whether outbound or return), AFKL reprices the entire segment, not just the individual flight you’re trying to change. For example, if your return journey includes a SH flight in J class and a long-haul LH in Z class, both flights are re-evaluated together. You cannot reprice just one flight on its own — the system looks for availability in the same fare classes to start with (like Z for long-haul). But if Z isn’t available, the system upgrades the fare to a more expensive class, which leads to a higher price — exactly what you’re seeing now.

You cannot just ask them to only reprice the LH, while not touching the married SH segment.