Not working on MAMP

Hi,

I use your awesome plugin on “true” web servers, and it works absolutely perfectly. Thank you for that!

However, I’m trying to install it on my local MAMP server on my Mac, and it just doesn’t work at all. When I active it, all CSS and JS disappear.
When I try to deactivate it, it works and the website displays all pictures in jpeg and no more in webp… BUT, on all my Swiper sliders loaded with lazy load (or not), no pictures in jpeg are loaded. So now, I can’t see pictures in my swiper sliders, even if I delete Webp express plugin.

Have you heard something like that?
I try with an other developper, and she works with MAMP too. But she sets a different url than me. Hers is WEBSITE.test and for me it’s localhost:8888/WEBSITE.
So it seems that it’s here the problem is coming, no?

Have you heard something like that?
Could you help me to fix that?

Thank you for your time and your help,
Have a nice day,

Thibault