I update a post and it creates a pingback? Any idea why?

I quote a sentence from WpBeginners about what a pingback is:

Pingback allows you to notify other bloggers that you have linked to
their article on your website.

So it means you probably have a link to someone else’s blog, which results in a pingback each time you update or publish a post in the above circumstance.

It can be a good practice if you want to notify other bloggers about you being interested in their content, they might want to link you back, or even add your website’s URL in their footer. This is one of the aspects of off-site SEO.