Batches Plugin affects to our main menus

Hi guys, Since we installed Batches Plugin something is messing with our menus. Let me explain: 1. If I add the item GROUPS (from buddypress) to my main student/instructor menus it alters the functioning of the whole menu. Note: I added GROUPS  because it is the only way for the student to see the batches they are included her/his, right? 2. If I navigate to GROUPS by clicking on the item on the menu  that I just added and then I go to one of the batches for that student the GROUPS item disappears from the menu. Like it was never there, therefore changes the whole menu disposition. 3. If I navigate to certain items on the menu, then GROUPS item disappears from the menu again. This happens not with all the items in the menu, just a couple of them that link to a pages. I mean, I do not know why when clicking over some of the buttons on the menu GROUPS dissapears and with other menu buttons it does not do it. It is random. 4. This happens only when GROUPS button is on the menu. If I delete the GROUPS button from the menu everything comes back to normal and the menu works as it should, with no errors or buttons disappearing. Please see image attached for more explanation.   Thanks in advance.