Mower doesn’t cut well in the centre of path

When I’m cutting the lawn with my new-ish mower, the centre of the path that the mower moves over, leaves the grass uncut (or cut higher). The edges appear fine. Does anyone know why this could be happening? Has this happened to anyone before? I tried to take a picture of this but the photos I took didn’t do it justice. Any advice on how to resolve this issue? Approximate location is Canada.