Walkways are supposed to tilt away from a house to keep rainwater away from the foundation.

But apparently you think the tilt is increasing? There are companies that fix this easily through the use of foam - they squirt foam underneath somehow and as the foam expands and hardens it lifts the sidewalk. I don’t know what this procedure is called (mudjacking?) but maybe someone else will chime in.

I would just leave it for now. It still looks good. Just keep your eye on it, in case it keeps sinking.