Weird behaviour with page's modified time

[snck]

I have a strange issue with a page's modified property. I am using the following code to get the timestamp of the last modified page's last modification:

$selector = 'parent.template=artworks, template=artwork, pj_kub_published=1, pj_kub_images.count>0, include=all';
$last_modified = strtotime($pages->getRaw($selector.", sort=-modified", "modified"));

pj_kub_published is a checkbox. It is used to determine whether a page should be visible or not.

When the checkbox is changed on a page and the page is saved, I expect $last_modified to represent the modification timestamp of the page with the latest edit (timestamp of page save).

This works if I check the checkbox (pj_kub_published=1) and save the page:

$last_modified = 1714047595

But if I uncheck the checkbox and save the page, the timestamp in $last_modified becomes some time in the past:

$last_modified = 1714030794

The date/tim shown in the settings of the page edit dialogue is accurate though.

This is really annoying because I am caching some output in files and use this timestamp to determine whether the cache should be renewed.

I have found no explanation for this behaviour. Already tried diabling $config->dbCache without success.

Without the selector the result is as expected and changes on every page save:

$last_modified = $pages->getRaw("sort=-modified", "modified");

Is there anything I am missing here or any other way to get an (accurate) timestamp of the last modification of certain pages using the api? Is there some kind of query caching involved? 

[bernhard]

Maybe I'm missing something but isn't your selector returning another page then?

If you uncheck the checkbox then you have pj_kub_published='' for that page, but you are selecting =1, so your page does not match and it will find another page having =1 and that obviously has a modified date in the past?

[snck]

@bernhard You are completely right! ?‍♂️ We can consider that solved, I guess. Thank you!