How to fix broken layout of Listings and Reviews modules
JReviews Listings Module and Reviews Module use bxSlider plugin for module pagination and slideshow functionality.
This plugin tries to automatically calculate the available dimensions for the slider within the parent element. In some cases this is not possible. For example, if you output the module inside a tab that is hidden by default, the module will not be able to calculate the available dimensions. To fix that, you can try to set fixed dimensions to the module's parent element. If that won't help, the only options are to publish the module to a different position where the dimensions can be calculated or to disable the pagination/slideshow. To disable the pagination/slideshow, you just need to set the Max. number of results and Results per page module parameters to have the same number.