random 500 errors on api-fetch when using wordpress plugins

Hello,

I have a problem with a WP site that I was asked to optimize.

On the homepage of different plugins (woocommerce, jetpack, matomo) I have random 500 errors in the console (on api-fetch sometimes all calls drop 500, sometimes 3/4).

I made a clone of the site at the same host (ovh), deactivate all plugins / themes but as soon as I reinstall woocommerce, I see 500 errors (less than in prod, 1 or 2 out of 19 calls for woocommerce) , and the more plugins I add the more 500 errors I get.

I looked at the memory side and increased WP_MEMORY_LIMIT to 512M.
phpinfo memory_limit: Local Value = 512M / Master Value = 512M

There is no change in the .htacces file. The content is basic.

I repositioned the file permissions to 664 and 775 for the directories.

Anyone have an idea to investigate further?

https://drive.google.com/file/d/1kDGBD6OjyyQQUer9vf3ta_bq8dJrkxAQ/view?usp=share_link

The page I need help with: [log in to see the link]