Hi @Nufa98,
Thanks for your detailed explanation, I am more than willing to help you out.
We can't actually hide "..." three dots, which is designed by SharePoint. We don't have an out-of-the-box way to hide it at the moment. Also, SharePoint has disabled script injection for security purposes, so we can't hide it through CSS scripts either.
We can remove the Not Following option by deactivating the Following Content feature, but this action affects all users and also removes this selection on the web side.
Here are detail steps to deactivate the Following Content feature:
- Contant your site administrator to go to your SharePoint Online site.
- Navigate to Settings > Site Information > View all Site Settings.
- Under Manage Site Features, deactivate the Following Content feature. This will remove the "Not following" option.
If you are very desperate to remove these three points, then you can use SPFx to solve the problem programmatically. You can add custom CSS scripts to hide content on the page via SPFx. However, SPFx requires some programming skills and can be complicated.
If you are new to SPFx, please refer to this article to get started.
If you have any questions, please do not hesitate to contact me.
Moreover, if the issue can be fixed successfully, please click "Accept Answer" so that we can better archive the case and the other community members who are suffering the same issue can benefit from it.
Your kind contribution is much appreciated.