If you place a reviews slider shortcode (or a block) on a tab that is hidden during the initial page load, it might not be correctly sized when the tab becomes visible later. This problem could also happen, if you place the reviews slider on any other area of the page (not necessarily a tab) that is hidden after the initial load of the page.

To resolve the problem with sizing of the reviews slider, it is necessary to trigger a resizing event when the slider becomes visible. For example, if the reviews slider is located on a hidden tab, then the resizing event should be triggered after a visitor clicks on the tab to make it visible. Here is a JavaScript code snippet that should be called to resize the slider:

jQuery('.cr-reviews-slider').slick('setPosition');

As WordPress is a highly customizable platform and every WordPress website is different, the place where this JavaScript code should be added will vary. Before adding this code, it is best to consult with the developer who looks after your website or with a developer of your WordPress theme.