It occurs to me that this might even date from last year.
Their IT systems have been abysmal, last year I placed an order for one of their specialty products. They had replaced the IT system and not even ported over the account data, I had to set up a new account. Well, welcome to the modern age, on-line ordering is actually functional! However, I was limited to ordering one case. At the time I didn't think much of it, just figured it was applying some dollar limit to what a new customer could order. Earlier this year I found it was still only possible to buy one case and an error code was configured for trying to order more than one--no explanation.
From https://datasembly.com/news/out-of-stock-rate-in-april-2022-... (referenced from https://arstechnica.com/science/2022/05/baby-formula-shortag...), we can see out of stock rates were already climbing to the 20-30% range in Feburary. It really ignites in April, as the recall affects products with expiry date after April 1 2022.