Sorry about that! Glad you're using telemetry though.
This is a known bug that we're looking into. In the mean time, saving the replay and viewing it later from Options | Forza TV will get you working telemetry.
Telemetry also works if you're viewing a replay from the leaderboards.
Edited by user Friday, September 11, 2015 10:13:45 AM(UTC)
| Reason: Not specified