Motor test confusing me even more

Rover 3.5.1
24v powered wheelchair base with Sabertooth 2x60 (dip switches - 1,4,5 down, 2,3,6 up - Independent mode)
Old 3dr pixhawk from an Iris+
Flysky FS-i6 6CH radio w FS-iA6B receiver

I have followed the documentation for setup and am stuck on the motor test.
When I click “Test all motors in sequence” both of my wheels turn, one at a time.
When i click motor A the left motor turns. The other motor does not turn for B, C, or D.

I disconnected the PixHawk and connected channels one and two to the Sabertooth and can control each wheel with elevator and aileron stick independently. Reconnected to Pixhawk (using iBus to RCin) and Motor test still gives incorrect motor movement.

Help!!! (please)

Hm, I am building rovers now many years and never once used the motor test (since it is available).
Does your rover work as expected in manual mode?
Why do you not update to the latest ardurover version?

No, it does not work correctly in manual mode.
I can not upgrade to the latest ardurover version because the recent versions will not fit on my pixhawk, the files are too big.

The latest version will certainly fit on a Pixhawk. Which Pixhawk do you have?

It is from a 3dr Iris+ quadcopter I believe from about 2014.
I’ve tried to upload 4.2,4.0,etc and they all say it’s too big. 3.5.1 is the most recent one I’ve been able to load on this pixhawk.

You just need to select the pixhawk1-1M variant of ArduRover

Thank you! I loaded 4.2.2 for Pixhawk1m and got no errors.

Now I’m stuck on accel calibration. When I start it nothing happens until it eventually times out.