Hey @AntoineB
For your first point you have, all the profiles in the screenshot were skipped because they failed the flow filter “Place order zero times” meaning they placed and order and were skipped. So the filter is working as expected. However the last skipped was back in February which indicates that there might be a issue with the integration and its periodic syncs.
Second, it appears there is a second indicator that there is a syncing issue as the Klaviyo profile does not show a Placed Order event even though WooCommerce is showing a completed checkout.
The best way to fix this is to completely remove your WooCommerce integration from Klaviyo and reinstall. You won't lose any data, and once you reinstall, all of the data that was missing (ie placed order events) will be added to profiles appropriately through a historic sync as well as allow for all new events to sync into Klaviyo.
Hope this helps!