Last seen timestamp for one of my contacts on whatsapp is drastically wrong, any way I can fix this?

Everything was fine until about a week ago when I realized that for one of my whatsapp contacts only I suddenly couldn't see their "last seen", and it only showed when they were online. I went to the contact info of that person on whatsapp and it said there that they were last seen 437 days ago. Each day this number progresses and I spoke to the person on whatsapp last week. Did they block me or something? Did this happen to anyone else and is there anything that can be done? P.S. For the rest of my contacts everything is fine, it's only this one person.