Mazda 3 , AT light

I own a Mazda 3 2010, have had problems in the past with the AT light. Just recently, the AT light has been coming on when the car attempts to shift into 5th gear. I do not drive the car in “slap shift”. Wondering if anybody can help me out

The owners manual should tell what this light means.

If it’s easy to do, first thing is to check the transmission fluid level.

I know what the light means, just wondering if anybody knows why it does that

Checked, and good