Question about Philips Avent Flaschenwärmer

I have the problem that the breast milk is always heated to over 42°C with my appliance. So I have to constantly measure with a thermometer when heating and wait until the 37°C is reached. Regardless of the milk quantity or setting. This is also the case with the keep warm function. Is this normal, or is the milk heated correctly (i.e. not too much)?