It’s hard to tell exactly without knowing more about how you’ve customized your templates, but it’s possible that this is a problem only with AJAX. A quick fix may be to disable AJAX pagination for the members directory. Do so by adding the ‘no-ajax’ class to the .pagination div, ie
<div id="pag-top" class="pagination no-ajax">
If you’re still having problems, please post more details about how your theme is set up – whether it’s a child of bp-default, which default templates you are overriding in your theme, and perhaps the content of the custom templates themselves.
