Resolved in: Layouts 2.6.7
On existing sites using Layouts you may find after updating to WordPress 5.6 in the backend that links or actions such as saving posts unexpectedly redirect to the add new Layout page, creating a new Layout.
This occurs with older versions of Layouts (current version for WordPress 5.6 compatibility is 2.6.7).
As a legacy plugin Layouts is currently missing from the custom Toolset installer page, and so you will not see update notices for Layouts.
Manually update Layouts with the latest version available at https://toolset.com/account/downloads
Download the zip file, then upload it to the Add New Plugins page of your site (where it will overwrite the existing version).
If you have problems accessing your plugins page (because of the issue described above), you may need to remove the previous version using FTP (or simply rename its folder to de-activate it).
You may need to clear your browser cache if still seeing the issue after updating, and if using any JS optimisation plugins, temporarily disable those.
The custom Installer has been updated to re-instate Layouts so you should now receive update notices for Layouts (as well as Views).