Competitor is intentionally leaving massive negative ratings on my blog

My blog is using Rate My Post as the default rating system. Recently, through personal observation, I found out that an individual (maybe a competitor) has been intentionally and continuously leaving negative ratings for my content. I have tracked the IP addresses using Rate My Post’s tracking feature and come to the realization that all the negative ratings (about 50 votes at this point) come from only one IP address. This person’s average reading duration of each blog article is only 3-4 seconds, definitely not enough for them to understand and give the articles a fair judgment, so it seems evident to me that their negative ratings come from malicious intent rather than being objective.

I would greatly appreciate any suggestions or solutions you may have to prevent this kind of abuse of the rating system. Maybe an IP block? Or something else?