Mini Cart: 'Edit template part' link doesn't work

[Aljullu]

I might be doing something wrong, but the Edit template part link doesn't work for me in WP 5.9-RC2.

If I have Gutenberg enabled, I get to this page: https://latest.local/wp-admin/themes.php?page=gutenberg-edit-site&postId=woocommerce%2F%2Fmini-cart&postType=wp_template_part

If I have Gutenberg disabled, I get to the same URL, but it doesn't seem to link to the site editor: https://latest.local/wp-admin/themes.php?page=gutenberg-edit-site&postId=woocommerce//mini-cart&postType=wp_template_part

I wonder if, at least one of the issues, might be related to #5519.

To reproduce

1. Go to Appearance > Site Editor and add the Mini Cart block somewhere.
2. Select it and in the sidebar click on Edit template part.
3. Notice the link does work.

Environment

WordPress (please complete the following information):

• Core version: 5.9-RC2
• Gutenberg version (if installed): disabled
• WooCommerce version: 6.3.0-dev
• WooCommerce Blocks version: trunk