u/Simple_Pitch2966

I am a new mazdaspeed3 owner, bought it stock (still is)

I checked the oil level the other day and it was below max. Now I looked again and it has risen up to the 'M' mark. I know this happens when you drive a lot on short trips (which I did a few times), but I'm also interested in what other possible reasons there could be and possible fixes, thank you!!