Strange behavior WordPress in multisite environment wicustomizer

[fkfaisalkhan007]

I am stuck with implementing customization abilities to the WordPress login page as it is a part of my plugin.
I managed to make it work on a single site, and all things are flawlessly functional. but with multisite, I am stuck with two things.

If you open this URL on a single site or a multisite,
​http://localhost/wptest2/wp-admin/customize.php?url=http://localhost/wptest2/wp-login.php

The first problem arises:

Single Site: The customizer will load the login page of your site in the customizer iframe.
But on multisite, load the dashboard of the current site.

The second problem is:
*On a single site, it works. if you try to change any customizer settings and press publish.
*But on Multisite, when you publish any change, it says, "You need a higher level of permission."
Note: With Customizer, if there is no URL redirection (​http://localhost/wptest2/wp-admin/customize.php), I am able to publish any change without any problem on any site.

Any help?

[sabernhardt]

Hi and welcome to WordPress Core Trac!

For help with individual sites and/or plugins, please use the support forums.
​https://wordpress.org/support/forums/

This seems related to #58610. If so, then the ​Multisite Custom CSS plugin might help you.

[hikmetadam]

Hello Sabernhardt, I had the similar problem after updating to 6.7 and tested Multisite custom CSS editor in WordPress 6.7, but it broke my site and required a fresh install.