Inventor 2040W + SparkFun U/S sensor problem

I’m using an Inventor 2040W as the basis for a robotic buggy. I have a SparkFun Qwiic Ultrasonic Distance Sensor (HC-SR04) which only works if I connect it using the 4-pin header on the U/S, connected to the header on the Inventor. (I had to cut the I2C jumpers on the U/S to disable the pull-up resistors in order to get it to work).

It doesn’t work if I use the Qwiic connector on the U/S connected to the Qw/ST port on the Inventor - should it?

Incidentally, I tried using a multi-meter to establish whether the Qwiic pins on the U/S are mapped to its 4-pin header, and I could only prove that Vcc and Ground were connected.