I need Siri to stop making suggestions/corrections to Calendar items

Hi,

I'm working with a shared calendar and Siri keeps 'correcting' the item to put it on the wrong date.

In this particular instance, it's an overnight flight, taking off one evening and landing the next morning in another time zone.

Siri -- despite being, so far as I know, disabled everywhere on both my Mac and my Phone -- keeps changing the date of this item.

In other words, is there a way to REFUSE a calendar change that Siri is making?