IP68 Waterproof 6m Ultrasonic Sensor bad max distance

We are using an ultrasonic sensor as a downward-facing sonar to measure the distance to the bottom of a swimming pool for 3D mapping purposes. Our main controller is a Raspberry Pi 5.

During testing, we have encountered issues with the sensor failing to read any values at depths greater than approximately 3 meters, despite the sensor being rated for a maximum range of 6 meters.

It accurately measures distances up to about 3 meters, but beyond this point, it only returns a value of 0.

Is there a configuration setting we should adjust to enable measurements up to the 6-meter maximum, or are there troubleshooting steps we can try to ensure the sensor achieves its full range?

Note: We ensured that the part we ordered is the 6 meter sensor so it should have a max distance of ~6 meters unless we were sent the wrong sonar on accident.

Attached is the Python code we are using to gather data from the sensor and publish it using a ros2 node. It is a python variation of the given sample code in the wiki.