Unable to click fields in ursim

Why am I often unable to click various fields in ursim? I’ve tried both 5.11.8 and 3.15.6 (by downloading the VMs from the UR webpage and running in VMware workstation player 16). See the screenshot below. Nothing happens if I click the “TCP X” field containing the value 0.0. Sometimes I’m not able to click any of the TCP related fields, and I can only click the joint positions.