You’re right! There was no escape. In The end, I Was forced to request the change to my provider. Thank you very much for The support!!
I tried adding a new php.ini in wp_admin, like someone suggest, but it raise a 500 internal server error (I think I’m supposed to have the original php.ini, change it and load it in wp_admin, instead of adding only the setting i need). I can’t access hosting features, by now. I don’t really now where to put an ini_set and I read that for this setting it doesn’t work if called this way, i mean run-time.
The plugin pointed out the problem. It was the max_vars, indeed. Htaccess setting seems not to be seen by the system. I’ll try a different solution. thank you very much!
Thank you very much! I’ll give a try!