Classic SharePoint features appearing on a Modern Site

Hi RMDUser1​ 

in this documentation you can see, how you set the modern experience in your library/list:

https://support.microsoft.com/office/switch-the-default-experience-for-lists-and-libraries-between-new-or-classic-66dac24b-4177-4775-bf50-3d267318caa9?WT.mc_id=DX-MVP-5004845 

And in this, on bottom, you can see the features that automatically switch to the classic experience:

https://support.microsoft.com/office/differences-between-modern-and-classic-experiences-for-lists-and-libraries-30e1aab0-a5cc-4363-b7f2-09e2ae07d4dc?WT.mc_id=DX-MVP-5004845 

Check the articles for a modern experience.

Best, Dave