[Chiuso] It takes about a minute to update a post which is not in the default language

Background of the issue:
I am trying to click on the 'Update' button in order to save the post, not in the default language. Link to a page where the issue can be seen: link nascosto

Symptoms:
It takes about a minute to update a post which is not in the default language. I expected it to save the post faster, but it takes a minute to save a translated post, while the same post in the default language saves in a few seconds.

Questions:
Why does it take longer to save a translated post compared to the default language?
How can I reduce the time it takes to update a post in a non-default language?
I already optimized the wtj_icl_translations, and it didn't help. I also updated all the wpml plugins.