Bottle fussiness

(For context, we ditched the perfect prep machine last week and have been making bottles the old school way for about a week). LO is 14 weeks old today and has become extremely fussy regarding the temperature of her milk - if it’s not warm, she won’t take it 😅 even if it’s warm when we start the feed and it cools whilst we burp her, she will refuse to take it back unless it’s starting temp again. Is anyone else experiencing the same? Have I made a rod for my own back for not sticking with the perfect prep machine temperature and making them slightly warmer? Is it a thing around 3/4 months for babies to become little divas?? 😂