I suspect this has something to do with the inferior intel modem that was used during the Qualcomm debacle. One of the main advantages of the next iPhone will be returning to a Qualcomm modem that isn't rubbish.
While I’m not a fan of what apple did it’s a bit disturbing that there’s literally just one company making cellular modems for US devices and that this company is really very hostile to users and device manufacturers.
They made the best modem for a price where many cant refuse. Or you could choose other modem from Mediatek, while it is stable enough, they often come very late in the cycle.