@chemuelmardie both the material and the operation 20 have red dots. This post goes over the meaning of the symbols in job entry E10 Job Entry Icons - #2 by nhutchins
I would agree with @NateS that looking in the job scheduling board could give you a clue. We have a Mold resource group that puts 4 hours of move tome for every operation. If someone put an very large move time on the resource or resource group it could move the next op a long way.