DIAGNOSIS This is almost always because the bevel scale's plastic pointer has shifted or the saw needs a simple recalibration. It's a common setup hiccup, not a broken part.
FIX You'll need a reliable square. First, unplug the battery. Loosen the two screws that hold the black plastic bevel scale (the part with the degree numbers) to the saw's body. Don't remove them, just loosen them enough so the scale can slide. Now, loosen the big bevel lock lever and tilt the blade all the way to 0. Place your square firmly against the blade (not a tooth) and the table. Adjust the blade until it's perfectly square. While holding it square, gently slide the plastic scale so the pointer lines up exactly with the 0 mark. Tighten the two scale screws, then re-tighten the bevel lock.
IF THAT DIDN'T WORK Check for sawdust or a small wood chip packed into the bevel stop, which is the metal tab the saw hits at 0 degrees. Clean that area out with a brush or compressed air.
HEADS UP The scale is just a reference. Always trust a physical square for critical cuts, especially for joinery. Check squareness periodically, as bumps in transport can knock it out.