No CSS in OceanWP installed demo

Hello everyone,

I am following the OpenClassrooms course about how to create a modern and professional WordPress website, but I have a problem with the OceanWP demos.
I installed and activated the OceanWP theme, and wanted to work on a demo first. But when I install a demo (I have tried several ones, the problem always shows up), it seems like there is no CSS at all. There is the text and images but no design at all. I have tried everything, reset my website, tried to downgrade Elementor, uninstall and reinstall OceanWP and a demo, nothing works. I also tried creating a website with Themecloud instead of creating it locally, did not work.

I created the website with Local by Flywheel.
My PHP version is 7.4.1
My web server is Apache (but I can switch to Nginx)
Database MySQL 8.0.16
OceanWP v1.8.6
WordPress v5.4.2

Please let me know if you have any clue on this situation.

Thank you!!