Before: Articles: Edit Category
After the alert: Edit Category

ah - I was just working from the screenshot will update soon

I have made the change - but - I think you will find that Add Category is also

Before: Articles: AddCategory
After the alert: Add Category

It is now $s: Edit Category. Changed $s to %s, but still an issue.

sorry - should work now but please check the Add

Warning: sprintf(): Too few arguments in \libraries\src\Language\Text.php on line 315

Sorry I am going to revert the last changes back to the original one. I am sure if you check the Add category you will see the same "issue" with before/after

Although we do need that string indeed when a 3rd party component does not have the "normal" string AND I agree with that patch, we should do better than that for core components as the issue is due to an incomplete redirect.

I looked at the urls produced
When first editing the category, we have
administrator/index.php?option=com_categories&view=category&layout=edit&id=2&extension=com_content and we get a nice title

but after reload because Associations could not be performed, we have
administrator/index.php?option=com_categories&view=category&layout=edit&id=2com_content and we get the "COM_CATEGORIES_CATEGORY_BASE_etc"

This is due to an error in the AdminModel.php redirects in the editAssociations($data) method.
Line 1659 on should be

			$extension       = $app->input->get('extension', 'com_content');
			$this->typeAlias = $extension . '.category';
			$extension       = '&extension=' . $extension;

and not only

			$extension       = $app->input->get('extension', 'com_content');
			$this->typeAlias = $extension . '.category';

Will make patch now.

See #27031

I have tested this item ✅ successfully on 9e1ca61

(Note: looks like we have the same issue in 3.x)

Obvious missing string. Tks.

Thanks