Firefox - FreeStyle - BX Slider doesn't display properly

[Prodrive (Lutz Cleffmann)]

On ecco-network.com we have been using the FreeStyle - BX Slider Stack for years without problems. But now with Firefox the slider is displayed in miniature size when you navigate form another page of the same site back to the home page.
As soon as you change the window width, it returns to the proper format.
Furthermore the stack is loading very slowly.

Normally the page looks like this:

If you navigate forth and back inside the site, it is displaying this way:

Has anyone experienced similar effects?
It’s only with Firefox. Everything ok with Safari or Chrome.

[robbeattie]

Sounds like a question for the author who I think is @willwood

[Prodrive (Lutz Cleffmann)]

I know, but before asking Will, it would be good to know if someone else also has this experience.

[willwood (William Woodgate)]

What’s your hesitation against upgrading to FreeStyle 3? It remains a free stack (if you’re using it in my themes). People tell me it works far better than previous versions and they love all the new settings I added like the Ken Burns effect.

https://themeflood.com/stacks/

[Prodrive (Lutz Cleffmann)]

Hi Will,

I don’t hesitate to upgrade. Just didn’t realise that there was a new version.

Thank you for your fast reaction.