I can confirm that changing the checked status by clicking on the "Checked" icon does not work. I have checked on a clean, current 4.3-dev branch with a new installation.

Maybe there is some relation to PR #39380 ?

For creating changed updated files I have proceeded as described in that PR. The SQL statements I have modified so the extension ID and so on are not hard-coded.

So I have created in the template manager in backend for the Cassiopeia template overrides of the default views of com_content/article and com_newsfeed/newsfeed.

Then I have run the following SQL statements to create the two changed overrides, replacing the #__ by my actual table prefix:

INSERT INTO `#__template_overrides` (`id`, `template`, `hash_id`, `extension_id`, `state`, `action`, `client_id`, `created_date`, `modified_date`)
SELECT 1, `name`, 'L2h0bWwvY29tX25ld3NmZWVkcy9uZXdzZmVlZC9kZWZhdWx0LnBocA==', `extension_id`, 0, 'Joomla Update', `client_id`, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP()
  FROM `j3ux0_extensions`
 WHERE `name` = 'cassiopeia' AND `type` = 'template' AND `element` = 'cassiopeia' AND `client_id` = 0;

INSERT INTO `#__template_overrides` (`id`, `template`, `hash_id`, `extension_id`, `state`, `action`, `client_id`, `created_date`, `modified_date`)
SELECT 2, `name`, 'L2h0bWwvY29tX2NvbnRlbnQvYXJ0aWNsZS9kZWZhdWx0X2xpbmtzLnBocA==', `extension_id`, 0, 'Joomla Update', `client_id`, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP()
  FROM `j3ux0_extensions`
 WHERE `name` = 'cassiopeia' AND `type` = 'template' AND `element` = 'cassiopeia' AND `client_id` = 0;

After that, I went to the Home Dashboard in backend so the Overrides Check were run.

Then I had 2 changed override files.

Selecting one or both files and changing the "checked" status with the action from the "... Check Overrides" dropdown action menu worked fine.

But toggling the status of one file by clicking the "Checked" icon did not work, even if the tooltip of that icon says it should work. I got the "No file selected" error message every time I clicked the icon.

Confirmed.

Closing as having a pull request. Please test #40397 . Thanks in advance.

I just tried to test this using the Patch Tester component and got this message:

"There are no files to patch from this pull request. This may mean that the files in the pull request are not present in your installation."

My overrides are in a custom template, not Cassiopeia

EDIT: Sorry - have also put this comment in the PR

@Scrabble96 You can't test the PR with patchtester because it changes javascript sources. To rebuild the javascript it needs a development environment with NPM. Or you use the patch package or custom update URL created by Drone for that PR.