Getting a "Internal error" while posting new event

Hi, I'm getting an error while posting a new event through API. This is the payload:

{'data': {'attributes': {'title': 'TEST 123', 'description': '<p>Questo è un test ma la descrizione deve essere breve.</p>'}, 'type': 'events'}}

As you can see there's an "è" that seems to crash the request: I get a 500 error with an html page.

I tried to use HTML entities, but then I had an 422 Unprocessable Entity error saying "1:19: FATAL: Entity 'egrave' not defined".

I hope you can look into this and sort it out. Let me know if you need more details!