Wechat can't see others' signatures.
The personalized signature column of WeChat is directly displayed on the WeChat personal page, and you can't set viewing permissions for strangers like a circle of friends. Non-WeChat friends can generally view your WeChat profile page as long as they can search or click. If you can't see it, it may be that WeChat doesn't have permission to open personalized signatures. Without permission, not only strangers can't see it, but even WeChat friends can't see it.