I think that the quote from the press release may be rather misleading. The report appears to be talking about pricing between retailers and their upstream suppliers. Apparently what happened is that there are various agreements between retailers and suppliers, and during the pandemic, some large retailers (think Walmart) placed the squeeze on suppliers who didn’t provide them with adequate supply. It isn’t complaining that Walmart wanted to raise prices for the consumer but somehow couldn’t until a shortage and then did so.