It is in fact the cliff sensors. There are 4 total. The two in the front appear to only be used for sensing cliffs, while the 2 along the sides serve a dual purpose of cliff and wheel off the ground sensing. In placing my reflective material over the sensors to bypass them, I found that you cannot place the reflective material directly on the sensor and instead must put it a bit off of the sensor itself. This is likely due to how the sensor bounces light at a 45 degree angle from the emitter to the sensor in it’s plastic housing.
I ended up using a white piece of paper with clear packing tape over it as my reflective surface and used simple scotch tape to hold them down. I made the pieces large enough to totally cover the entire sensor and taped them so that the sat at an angle from the end of the sensor at the bumper to the main chassis of the robot. This appears to be working.
@WyzeYun @WyzeDave @WyzeDongsheng This is a dumb problem to have. Black accented or very dark rugs/carpets are extremely common place. This should be a very simple fix of bypassing the cliff logic as a setting override. A fix for this should not take more than 15 minutes to implement assuming the cliff logic is a called function, simply add an if statement to the call of the cliff logic and if it is disabled, don’t call it. How this has been a known issue reported by customers for over two years now should be an embarrassment.