Oops, I had the wrong datasheet in hand, but the datasheet for the 7455 says the max current draw is 1.5A (page 47 of the technical specs), although they say the maximum average current is 1A.
The moral of the story is that powering LTE modems via USB isn't plug and play. If you want to make sure your LTE modem doesn't periodically crash, make sure your power source can handle it.
And if you are looking to power a high performance LTE modem from USB2, you'll definitely want two USB connections.
Oh, BTW, ltefix.com is shutdown due to supply chain disruption. They were selling stuff on facebook, but they've shut that down too. The last I heard from them, they hoped to be back in business in a couple of weeks.