Cannot move page back to root folder

__Grav v1.7.34 - Admin v1.10.34__
__OS: FreeBSD 13.1; NGINX; PHP 8.1.5__

Using the Admin plugin, I can create a new page in the root folder. I also can move it under a different parent but cannot move it back to root. Error: Forbidden.

This is how I can reproduce the error:

## Step 1 [Creating a new page with default settings. (works) ##

## Step2 [Moving page under different parent (works)] ##

## Step 3 [Moving page back to root-parent] ##

## [ERROR] ##

Please advice.
Thank you