Our oven consistently undercooks food
Oven temperatures are conventions and really mean little.  Plus, typical home ovens vary widely, so that when you set the dial to 350, the interior can easily fluctuate between 330 and 370, and that is when your oven is correctly calibrated, which few are! So, it is probably not getting to the temperature that the readout says.  An oven thermometer can help get you in the ball park...but...no big deal...You are on the right track using a thermometer to measure the internal temperature of your food. Be sure to calibrate your probe thermometer to make sure it is accurate.  Then, you are just going to have to get a feel for your particular oven, by setting the temperature a little higher and/or leaving food in a bit longer.  Take note, and you should soon recognize a pattern that you can work with.