@dorilama I tried to run the page with
https://mydomain/page?debug_mode=true&bubble_no_third_party_plugin=true&bubble_safe_mode=true
and it worked! The only plugin being used was an “Airalert” which is appearing also in that workflow.
I then reloaded the page without those parameters so to reactivate the plugin and it worked!
I guess it’s a problem related to corrupted cache as pointed out here:
Thanks to all of you.