Hi,
This a current limitation of Path Tracer and Twinmotion's water materials. This is something that is planned to be improved in a future update.
One of our community members has shared a workaround they use to fake the effect of transparent water in Path Tracer in the following post: Water TW 2022.2 You may find it helpful to try the method they suggested for the meantime.
Best,
Raghib