UR5e unable to compute motion generation or reachable pose near ground objects

[PGannonGoddard]

Hello,

I'm working on setting up a pick and place task using the provided UR5e files in this package. Testing out the models with some of the example code, I found the UR5e consistently unable to reach poses near the ground/table obstacle. To observe this, I ran the example omni_python ik_reachability.py --robot ur5e.yml --visualize_spheres and moved the target to ~0.04, placing it just above the ground. This was also observed when using MotionGen.plan_single() in other scripts.
In addition, I also extended the tool point of the model out by ~0.1m (in the URDF file) to separate the end effector from any potential collision sphere located nearby. This resulted in identical behavior, with poses near ground being "unreachable". This was also compared to the Franka setup with the ee_link_name="right_gripper", which was able to make the computations that close to the obstacle. Could this be be an issue regarding collision sphere configuration of the models, or could it be a parameter of the motion generation / IK solver that is too constrained?