Hi,
Sorry, I didn’t have time to send a message back.
As indicated, I activated the indexing cache: Caching Options > Caching activated + Caching method > Database
In the meantime, I realized that I also had to change the option: Search source > Post Type Search > Search engine > Index table engine
And since indeed, it is very fast, but I do not know if it is a good use or an element which makes it possible to identify the source of the problem in the event of use of the regular engine.