Hello,
Thanks for your Patience!
Flex-Sliders are Flexible Sliders and the Size of the Flex-Sliders depends on the size of the Images added to it. If you consider using a Max Viewport Height for the Sliders, there is no guarantee if the Images will display all its properly and usually it is centrally aligned. You can consider using the following code:
<div class="fslider" data-arrows="false" data-animation="fade" data-thumbs="true">
<div class="flexslider">
<div class="slider-wrap">
<div class="slide max-vh-75" data-thumb="images/portfolio/single/slider-thumbs/7.jpg"><img class="object-cover" src="images/portfolio/single/full/7.jpg" alt="Slider 2"></div>
<div class="slide max-vh-75" data-thumb="images/portfolio/single/slider-thumbs/1.jpg"><img class="object-cover" src="images/portfolio/single/full/1.jpg" alt="Slider 1"></div>
<div class="slide max-vh-75" data-thumb="images/portfolio/single/slider-thumbs/10.jpg"><img class="object-cover" src="images/portfolio/single/full/10.jpg" alt="Slider 3"></div>
</div>
</div>
</div>
This Codes uses 75% of the Viewport for the Sliders using the .max-vh-75 Class. You can consider using these Classes: https://docs.semicolonweb.com/docs/utility-classes/heights/ if you choose to use a different max-height.
Hope this Helps!
Let us know if we can help you with anything else or if you find any further issues.