First I've heard of this. Exactly how many tons, and how much shipping volume/tonnage was wasted?
There have been attempts to estimate this. They founder on the problem of the US British not preserving every single cargo manifest for every cargo on every ship. Actually the records during the war were very incomplete. Historians cannot do more than make rough estimates on how much shipping capacity the Allies had in any specific month from 1943 through 1945. There are some samples collected from specific locations & periods that suggest the amount of waste.
This is not suggest anyone else were paragons of efficiency. Samples from Axis or Soviet logistics records show 'snapshots' of significant wastage.
In the case of the Western Allies two common sources of shipping cargo waste were: A. poor tracking and dispatch of cargos. Material would be loaded on the wrong ship, or the ship receive incomplete or wrong orders on where to deliver. that led to stuff being dumped on some dock or beach far from its intended destination.
B. Another problem was inadaquate receiving facilities at the destination. that led to cargos requiring dry storage dumped in the weather, or to ships parked in a harbor for months until storage was available or the cargo spoiled. A example of this last problem was the port of Antwerp in mid December 1944. Approx 19,000 tons per day were being unloaded in the first two weeks of the month, but the rail, barge, auto transport was clearing a average of less than 15,000 tons per day. Antwerp lacked extensive warehousing & the port ops commander halted most discharge in late December to clear the backlog ashore. That led to cargo ships that had been dispatched weeks earlier stalled in the Scheldt Estuary or waiting on other ports & anchorages. By the time discharge ramped back up in mid January over 20o cargo ships were claimed to be stalled all the way back to US ports. A similar problem had developed in July 1944 when the French Atlantic ports were not captured when the logisticians had expected.