I agree that aperture equals aperture-but ISO has been changing higher over the years and that helps make the amount of light available in newer cameras important especially in lower light applications.The technology really changes the equation of the magic triangle of shooting-my Sony RX100 also has a lens of 1.8 in point and shoot with a 1in lens so modern technology makes more light available. Cell phones use it too by helping low light shots but sacrifice shutter speed and iso usually.
It's more complex today than just Looking at lenses apertures! Newer cameras bring much more light while keeping very sharp quality shots. Sensor technology is much more a part of the equation when I shoot at 300mm I can now go to 2000 iso and find little change in the resulting quality, which helps the f5.6 aperture opening at a faster shutter speed-why buy the faster more expensive lens when I still need more light? although- The quality of the larger lens will bring out more detail by its very design. Olympus has designed about as much quality as one can get with 4/3 sensors and high Iso design-in my opinion. But that's not the topic. Just saying times they are a changing!

Try to set the focus on center point -then check it on manual and see if it is better. Maybe go to menu and do a camera reset the kids may need to reset the cameras after another student messes with the menu-center point focus is the default setting for sharpness-that and getting them to see the point of focus on the screen itself. They are just beginners -baby steps.They need to learn the ap.shutter speed ,and Iso, concepts first-I make them shoot Manual to learn this. Good luck it's a steep learning curve of at least 3 lessons! But it pays off for those wanting full expression. I try not to flood them with too much at once, but the students who are serious will appreciate it.