Due to the quantity of information on the page, the site editor may have problems when rendering blocks. This behavior occurs intermittently, sometimes components are not rendered and sometimes it's rendered twice. It can happen that no blocks will appear at all on the site editor:

Or it can happen with fewer blocks.

You can also experience a delay after saving new content. The content is saved but the screen will keep loading:

1 - Try editing Site Editor, sometimes it won't be rendered and sometimes some blocks will be rendered twice.

2 - Try saving a content change, the content is saved but the screen will keep loading

No known workaround is available.