My experience is that it gets duplicated about half the time, and I just delete one of them. Sometimes one or the other doesn’t show up in strava. I don’t know why, but maybe Strava has a built in algorithm to avoid duplicate activities that catches it. I also noticed that while a non-TR zwift ride will make it to my TR calendar, if I do a simultaneous TR-zwift ride, only the TR activity makes it to my TR calendar, which is fine by me.