Hi.
I noticed that k2 feeds don't update when i add new articles.
It seems like the feed listitem is generated once on a first visit and then no new items get added.
However, when i introduce changes to articles, the feed changes as well. Just no new feeds appear after first visit.
Obviously, i excluded cache issues from the culprit list.

I reproduced this error on two different installations of Joomla with K2 component.
I also checked the feed for regular categories/articles - they appear in rss feed no problem after being added.
new k2 articles appear ok in the frontend, only when i add ?format=feed&type=rss to the URL i cant get the correct feed from category.

site in question:
4tour.pl/szczawnica/wydarzenia-regionalne-szczawnica
with a sample feed
4tour.pl/szczawnica/wydarzenia-regionalne-szczawnica?format=feed&type=rss

Im running out of ideas here.

Hello,

What are your caching settings Jerzy?

disabled in global-> system settings
module -> no caching as well

I just tried to reproduce the problem on a fresh installation.
I created a simple k2 category and added some items - so good so far: the feeds get updated.
Then I decided to go further and imported the following tables from problem site: #__k2 items, #__k2_categories, #__k2_extra_fields, #__k2_extra_fields_groups.
Yup. the feed problem has been reproduced.
I would attach sql dumps but the 'add file' button doesn't seem to respond.

Which other K2 related extensions are you using?

fresh install. only k2

I mean the site that has the issue.

k2 tools
k2 users
k2 user
k2 comments
k2 filter & search module

all enabled

Can you deactivate the k2 filter & search module and see if the issue is resolved?
In the link you sent me - 4tour.pl/szczawnica/wydarzenia-regionalne-szczawnica - the very first item is REDYK – Tradycyjny przepęd owiec po okolicznych halach
In the feed this is the item displayed as well, this means that the output is correct.
Have you tried adding a new item?

PS, Since the actual output is being generated by Joomla!, the feeds will not abide to the filtering options (which use CSS to only hide/show items), the first items (in relation to the DOM) will always be shown.

unfortunately, no changes.

The "REDYK – Tradycyjny przepęd owiec po okolicznych halach" is still first in the list.

The end-user might see a different item but the first item rendered in the DOM is still REDYK – Tradycyjny przepęd owiec po okolicznych halach

That's my point. On the frontend category view we have new item "Święto Ulicy Szalaya" which doesn't show in feeds

enough for today, ill come back to this tommorow

Święto Ulicy Szalaya is not the first item. It shown first because of the filter extension. Please view the site's source.

then, how can i set ordering by publish date?

You need to change this setting in the category's settings.
If you are using a multi-category menu item, then this setting is located in the menu item's settings.

You're the man, Krikor

Thanks a lot for your help!

You 're welcome Jerzy :)