Posts to group don't appear on the dashboard unless I go to Timeline

Hello,
I added a welcome post to a group and it's very important that that post appears for the users accessing that group for the first time. However that post appears on one occasion and then disappears on another and it's very inconsistent and the only thing I managed to figure out is that if I go to the group, it doesn't show, and if I click on the Timeline in the sidebar - it appears (well, almost always at least). Thanks for looking into it,
Michael

edit: If you stay on the group page long enough, you will get notified of an update and a grey bar will appear where you can refresh and see that post. However that is after a long while so that obviously doesn't work the way it should. Plus after a while I get that again and get the posts appear multiple times.