Hi there,
Thanks for reaching us and we are sorry for the inconvenience.
In your given URL, I couldn’t find any filter options. Maybe you have deactivated those? If Yes, please activate them again so that I can check the issue visually.
On the other hand, have you done the settings of the gallery properly as per our documentation? The issue you have raised is very strange and it should not be happened because we have tested it many times at our end and it works very smoothly. Please, have a look to this documentation once again and check if everything is OK or not: https://essential-addons.com/elementor/docs/content-elements/filterable-gallery/
Looking forward to hear from you soon!