I use Siri a lot, to manage my life and even for work. I’m frequently setting reminders as I think of them, when driving or doing anything else, by saying “Hey Siri... set me a reminder for (such a thing) at (whatever date and time) and find his help very useful and low maintenance.
I was somewhat alarmed however that one day last week Siri spoke in a completely different voice and seem to have a completely different personality! Gone was the pleasing well modulated and respectfully polite English gentleman who is usually so helpful. In his place was a deeper voiced, smooth, sardonic and smug sounding sleaze bag who gave borderline sarcastic responses. He actually sounded quite passive aggressive. I was alarmed every time I spoke to him!
The following day I was most relieved that Siri was back to normal! I did have a quick google but could only find information about changing Siri’s voice to your own preferences in your settings. I didn’t do anything like that and when I checked, the setting was the same as always
Has anyone else experienced a bipolar Siri?? Or am I completely losing the plot? 
Am I being reasonable to feel that in this uncertain world, where people are moody and sometimes quite inexplicably behave like arseholes, that an artificial intelligence such as Siri should be consistent?!