Press the temp button and the up arrow

I'd already packed up our new Cuisinart convection oven toaster broiler to return to Costco, but thought I'd first check the book for the instructions about setting temperature. My wife and I had tried this morning to set it at 350 to bake my Mary B's buttermilk biscuit. "Press the Temp button," she'd said, "and hold it down while you press the Up arrow." The starting temperature of 150 hadn't moved. We tried it several times. Once the temperature moved up to 175, another time to 175 then 200. But mostly it stayed stuck on 150. Twenty or thirty minutes later, the biscuit had come out a sodden lump of visually unappealing dough.
    I quickly found, on p. 3, under "Quick Reference Oven Operation," the instructions to:

•  Press Bake or Conv Bake
•  Press Temp
•  Press Up or Down arrow to enter temperature
•  Press Start/Stop to start oven

Hmm, nothing about continuing to hold "Temp"....
    I took the book to my wife. "Where did you read that about holding Temp down while pressing an arrow?"
    She took the book and said, "Right here, on. p. 6, under convection bake: 'Press the Temp button and the Up arrow to increase the temperature.'"
    "At the same time?"
    "Of course! It says, 'Press the Temp button and the Up arrow.'"
    I showed her p. 3 and said, "I think they probably should have said to press the Temp button, then press the Up arrow."
    "Okay," she allowed, "let's try it."
    I unpacked everything and she plugged it in. Then she pressed Bake, then Temp, then the Up arrow a few times.
    Voilà! The temperature read-out rose to 175, 200, 225, 250, 300, 325, 350.
    I said, "I bet the times the temperature moved up before, we weren't holding Temp down at the same time."

Siegfried and I didn't have to drive to Costco!