If you didn't see it, that may be because FB have made more changes to their algorithm (what a surprise!) which means that you're less likely to see PmP posts. Before, group posts were usually shown to most people. We regularly had 80% or more of our members seeing each post. 50% was low. Now, however, it's more like 2 or 3% who see each post. In fact, one recent post was only seen by 1 person! Our main page reach has gone down recently, too, from 50 - 60% to as low as about 10%.

 

It's been the case for a while that FB thinks you are no longer interested in a page if you don't interact regularly.  That means liking, commenting or sharing a couple of times a month.  (Sharing also increases the reach - worth remembering if your design is being featured!)  However, it seems that even that is no longer enough.