After moving that sensor from pin 1, I think that the next thing that I would do is to reduce the wire length and use 10K pullups just to test.
Ok, I will try this.
Are you sure that the Pi is capable of supplying sufficient current for the Uno and sensors. The Uno alone needs about 50mA the sensors 1K pullups about 5 mA each + 2mA when each is measuring.
Maybe I should try also to power supply the Arduino with an external charger.