Hi. I have an AE-1 that I used for many years without problem. When you take a picture of a landscape, does the picture come out exposed OK? If so, you camera is probably metering OK. A landscape is close to an "average" scene, which is what your camera was designed to meter.
However, if most of your frame is filled with a very dark subject, the camera thinks this is an "average" (18% grey) scene so your film will end up being overexposed. If you take a picture of a mostly white scene, the camera will underexpose, making a very dark subject appear grey. This is normal for most cameras/meters. You as the photographer will have to recognise when to give some exposure compensation.
I have a black dog and a white dog, and it is very diffivcult to take a close up picture of either of them because of the under/over exposure problem when photographing a scene which is not average. I get around this by either manually setting the aperture and shutter (if they are sitting still), or by having a dog only take up a smaller portion of the frame. I will have to crop the picture later, but at least the camera will meter for an "average" scene and the dog, either one, will come out pretty good in the final picture.