Enfamil RTF gentlease separating after warming

Hi - I need some help figuring this out. I started gentlease ready to feed formula for my LO and I use dr browns warmer to warm it up. And I follow the instructions in it. 2.30 for 4oz if room temp and 3.55 for 4oz if refrigerated. For some reason I have noticed white specks and even separation (white liquid on the top and yellow clear liquid in the bottom) after warming it up for a while. Although when I mix it, it looks like regular ready to feed formula. Is this normal? Did I receive a bad batch? And is this the right way to warm the formula? I have so many questions. Any insight on this is appreciated.