Distance Sensor not working

It used to work, but now it doesn't.
When I say it used to work, I mean that it worked (and still works) with the 32-bit Lite OS and the 64-bit Lite OS.
When I say that now it doesn't, I mean that it doesn't work with the 64-bit Full OS.

I click on start distance data but I don't get any distance_mm values.

The sensor (kind of) works. The first time I run robotpython robot/tests/test_distance_sensor.py, it just prints "Initializing distance sensor...".

If I close that ssh session and try again, it works:

doug@raspi4:~ $ robotpython robot/tests/test_distance_sensor.py
Initializing distance sensor...
Setting distance sensor resolution and frequency
Starting distance sensor ranging
71 75
73 72
74 71
71 73
74 72
76 71
75 71
74 73
72 75
74 73
74 72
72 71
76 75

Reproduce the issue on the 64-bit Full OS and compare it with the working 32-bit and 64-bit Lite OS setups. Start with robot/tests/test_distance_sensor.py and the reported first-run behavior; done means the sensor produces distance_mm values reliably on the 64-bit Full OS.