About half the time or more when dictating text, if dictation mode is manually deactivated immediately when done speaking the last word is duplicated.
For example, if you dictate a text message (without using Siri) using the microphone button on the keyboard and are dictating a text message to someone by saying, ‘I’m on my way, be there soon.’
and hit send or stop the dictation as soon as you are done talking the dictated text will read.
‘I’m on my way, Be there soon soon.’
-currently running iOS 18, beta 1 and I’ve experienced this multiple times.