Well, if you pull up the report, it says "This study did not test whether the specific companies that received 6(b) Orders increased their prices by more or less than their input cost increases". So .. they don't actually have any data that says this, from the grocers they studied.
What they're instead going on, from the report, is looking at grocer's profit numbers (which they never provide a source for): "Specifically, food and beverage retailer revenues increased to more than 6 percent over total costs in 2021, higher than their most recent peak, in 2015, of 5.6 percent".
So .. before the pandemic they had peaks of up to 5.6% over cost, and the year after the pandemic they were at ~6% over cost (also, what does "more than" mean? Why not just write the number? They had no problem writing 5.6%, why not write 6.1% or 6.7% or whatever the number is?).
Ok? So basically the same with some minor, less than half a percent variation? Where less than half a percent of difference could be explained by a multitude of factors? Seems like the year of covid and year after covid had virtually no impact. The (slightly) more interesting figure is that in 2023 (why was no 2022 data point included, did it not fit the narrative?) the rate was ~7% over cost. But multiple years on from covid I'm not sure what the connection to covid is at that point.
Also .. isn't it extremely basics economics that when supply drops but demand stays the same or rises, this should result in higher prices? That's exactly the scenario we had in covid. If prices only rose less than half a percent more than pre-covid profit peaks, doesn't that say something extremely positive about the grocers? If they really wanted to "take advantage" of the consumer they could have raised prices to make demand drop to match the supply, for example instead of selling out of toilet paper, selling them at $100 a roll, $200 a roll. That's not remotely what happened.