Sensor coordination problem when PnP

Sorry because I am still struggling with this process. Here is a problem I do not know why it happened. It appears that I cannot connect the sensor here perpendicularly to conveyor, although in previous saved files that is really easy. The PnP mark turns green but the coordination is slanted and I cannot change that. I just create a new interface, in addition to default ones for this main conveyor but as far as I know, the problem here may not relate to that. Please help me with this. Thank you very much.
The simulation can be found here:
robot1_1.14.vcmx (17.4 MB)