Date Time Stamp Applescript formatting result is odd in Sonoma

The following seems a little more direct for showing the date:

display dialog (current date) as string

But you're probably trying to insert that date into some app?

If I run your code directly in Script Editor, I get error -1721, which means The wrong number of arguments was detected. Which undoubtedly means I'm not using the same app you're scripting.

on run {input, parameters}
    set thedate to (current date) as string
    tell application "System Events"
        keystroke thedate
    end tell
end run

I'd guess you're meeting something with the string or the encoding or the unspecified app.

Above tested on macOS 13.6.3.