Ellie here has been tasked to sweep Sedimentary Rock. There was 100kg at every square on the floor of the room where the cot and lamp are. She's grabbed 300kg but there's another 300kg on the floor in three 100kg piles. Extremely inefficient.
Her carry capacity is shown on the red outlined section that I edited into the screenshot.
To be honest this could be a problem in the base game also, but I'm running Spaced Out so that is where I've reported it.
I can upload a save if need be.
Have a dupe with high carry capacity do a sweep task where there is 100kg in each square across the whole floor. The fupe only picks up three of the 100kg chunks before running off to deliver.