I use the package for SEO, it's great

but sometimes you need to disable pageNumber

this packages adds the page number if it's > 1

It's not a bug. I thought about creatating a pull request with option to disable adding the page number to the title but I'm not sure if it's required.

There is another option.

layout: page
data: collections.tagList
size: 1
alias: tag
permalink: blog/tags/{{ tag }}/
title: Articles tagged as {{ tag }}
pageNumber: -1

Just add pageNumber: -1 in eleventyComputed

I don't need pageNumbers. I displays a list of tags, single page.

It works for me.