Check your filter settings in your group page. More than likely, filters are turned on and some of your group types are being hidden.
Go to your groups page
Click the Groups Filter option (located in the middle of the page)
Choose which type of group(s) you want to show by checking the box next to the type.
*Please note this is a "sticky" setting. What you choose to show will be remembered the next time you go into the groups page.