I2C Error with Bump Sensor

Any ideas why I would get I2C errors with bump sensors? I understand if motors/sensors become disconnected you can get that but we have tried multiple sensors and multiple data wires. It’s the only thing plugged into that range (7-9). We are running RobotC 4.52 and per the firmware utility, no bumper sensor is listed to upgrade.

Bumper sensor has very little electronics inside and no CPU to upgrade or even talk I2C protocol. You mentioned using empty port triplet for testing, that’s important to check for some issues.
Have you tried the bumper on an otherwise completely disconnected brain?
What do you see if you disconnect everything and only attach the bumper to port1?
Any error on boot?
What does Device Info (turn on the brain, press ‘X’, “down”, “check”) show in such situation?
(You should see no error, “Port 01 Bumper” with current state reported in device info and no other device seen on any other port).