Keyword issue in General Settings Within Post Settings

Hi,

I’ve just activated the Plugin.

Problem: When I enter a post to set up the keyword in the general plugin settings next to the post the keyword appears. However, when saving and re-opening the plugin setting section in the post then, the original example ‘Rank Math SEO’ would appear again in the field instead of my keyword. I’ve run it a test with two posts.

What may I change to have my keyword stays in place?