We’re sorry to read you’re facing this issue. It’s indeed problematic for a community website if user cannot register properly.
Maybe these topics will help you to solve your issue as they seem to answer the same concern:
Please note that this issue is related with the customization of a third party plugin, not with the use of your theme. Moreover, our theme doesn’t affect this feature. As theme authors, the installation, setting or debugging of third party plugins isn’t part of the support we will provide.
To go further, we invite you to ask for more help from the plugin authors and post your request on their support forums:
We remain available for all support requests related with the use of your theme.