Distance?

I’ve seen posts related to speed discrepancies, if I remember correctly, but nothing to my memory to do with this:

Just did Tempo 4X12 (stopped at 2:00, didn’t do the whole activity).

Distance clocked in at 34.8 miles when I finished but uploaded to Strava and shows in my calandra in SYSTM as 36.22 miles.

Any insights as to why would be appreciated.

Happy suffering