The default 2020 Mason copyright text remains in place. Anything that I have added to the footer text area including the dynamic copy and site title are not added in place of the default text.
Thats because the default footer has been replaced by the Block Element i mentioned above.
Go to Dashboard > Appearance > Elements and edit the Footer block element
The Block Element is quite new and is a great way if you want a more designer footer.
If you want to keep the Theme Footer including the copyright bar, you can edit the Block Element and change it from Footer to Hook > Before Footer.