Hi, I have this problem too. It specifically happens when I do the following:

1. Ride on Peloton
2. Auto-Sync to Strava
3. Download .tcx from Strava
4. Upload .tcx to TrainingPeaks.

You get the speeds and times but you don't get the power or the heart rate.

I was advised by TP tech support to use a 3rd party conversion tool ("goates"). This worked - it created a new TCX file that TP was able to read *and* extract power/HR.

Here is a single trackpoint from the original file:

<Track>
<Trackpoint>
<Time>2025-03-13T19:50:02Z</Time>
<DistanceMeters>7.08</DistanceMeters>
<HeartRateBpm><Value>94.0</Value></HeartRateBpm>
<Cadence>53.0</Cadence>
<Extensions>
<TPX xmlns="http://www.garmin.com/xmlschemas/ActivityExtension/v2">
<Speed>7.17</Speed>
<Watts>97.0</Watts>
<Resistance>97.0</Resistance>
</TPX>
</Extensions>
</Trackpoint>

And here is the same trackpoint after conversion:

<Trackpoint>
<Time>2025-03-13T19:50:02Z</Time>
<DistanceMeters>7.08</DistanceMeters>
<HeartRateBpm><Value>94</Value></HeartRateBpm>
<Cadence>53</Cadence>
<Extensions>
<ns3:TPX>
<ns3:Speed>0</ns3:Speed>
<ns3:Watts>97</ns3:Watts>
</ns3:TPX>
</Extensions>
</Trackpoint>

These are fairly simple differences. Your engineering team should be able to handle these on import.