Slides won’t open in LayerSlider since the update

Since the last update (7.1.3), the slides in LayerSlider won’t open on our English website. I just get a spinner thing.

I have multiple “beta” English websites that I updated and they all have the same issue, even though there are no new plugins on those.

Only one plug-in (Fluent Forms) has been added to the production website. I did try disabling that plug-in and there was no change.

In contrast, the French website is also updated to 7.1.3 and the LayerSlider works fine there and on all the French beta versions.