Here's the actual study:

https://www.tandfonline.com/doi/full/10.1080/17538947.2024.2329816

Of over 13,000 islands examined, approximately 12% experienced significant shifts in shoreline positions. The total shoreline length of these islands approaches 200,000 km, with 7.57% showing signs of landward erosion and 6.05% expanding seaward. Human activities, particularly reclamation and land filling, were identified as primary drivers of local shoreline transformations, while natural factors have a comparatively minor impact. Moreover, the ongoing rise in sea levels is identified as an exacerbating factor for coastal erosion rather than the primary cause.

In other words, the study found that between 1990 and 2020, reclamation and land filling had a much larger impact on island size than rising sea levels.

Which is not remotely surprising and certainly doesn't "disprove" claims of rising sea levels. In fact, the study fully accepts that sea levels have risen. Because they have.