Site title is added at the end of each permalink automaticlly

Hello WP forum,

I’ve been using WordPress without any issues for the past year and a half. However, I recently encountered a problem that I suspect may be caused by either the Yoast plugin or WordPress itself. My permalink structure is set to “post name” to create cleaner URLs like “sitename.com/post-name.” Upon analyzing my website for errors, I discovered a peculiar issue. All my pages had duplicate URLs with “/site-title” appended at the end, resulting in 404 errors. An example of such a URL is “sitename.com/post-name/site-title.” I attempted to resolve the problem by adjusting the settings in Yoast, but the issue persisted. I also reached out to my hosting provider, but they were unable to provide a solution. Currently, I’m manually redirecting each URL to its original version. I’m concerned that this issue may negatively impact my website’s ranking. I would greatly appreciate any assistance from the WordPress or Yoast support teams.

To provide more context, here are the settings I’ve configured and changed in WordPress:

• Permalink setting: https://ibb.co/R6QbNq9
• Yoast settings I modified or disabled: https://ibb.co/4TfnkRZ
• 404 error: https://ibb.co/bHktmP0

I kindly request support from either WordPress or Yoast to help me resolve this issue promptly. My website is performing exceptionally well, and I want to avoid any potential problems.

Thank you for your attention and assistance.

The page I need help with: [log in to see the link]