I have the same problem,
It appears that the first page of members is reached with the following URL
https://my website url/index.php?option=com_community&view=groups&task=viewmembers&groupid=31&Itemid=129
but subsequent pages use the url
https://my website url/index.php?option=com community&view=groups&task=viewmembers<emid=129&limitstart=20
Note that the groupie parameter is missing from the second URL.
If I manually insert it the correct second page of members is displayed.
I'm trying to work out whicjh module actually sets the URL up.