Using Sitecore 9.3
When I assign security roles - either by going to an item in the content tree, or by going to the role manager, selecting item, and clicking on assign, I can make changes, but those changes are not saved. As soon as I close the dialog, changes are lost. I do not see any errors in the logs or in the browser console.
UPDATE
I am making changes as a user with Admin checked (Although not the user Admin).
So, the issue seems to be with the Assign Security dialog. For example, if I go to the role manager - Security Editor, select an item and click READ, that gets saved. But, if I select the item, click Assign, then try and make some changes, those do not get saved. The same is true in the security section of an item in the Content Editor. If I click on Assign Security, then make changes in the dialog, the changes do not get saved.
This happens for Roles, Users and individual items. Looking at Raw values, there are values in raw values for normal changes.
UPDATE 2
It does look like I can edit the raw values and see my changes. Can I make changes in raw values? I would need to better understand the syntax.