Had similar issues, today… Win10 box died, so tried to pivot to iPhone to record workout.
Finally had to uninstall / reinstall TR to connect to speed/cadence sensor… but never would see HR strap.
I’m an IT Admin (cloud systems) and a former Ent. Mobility Manager… and I wound up with a burger instead of a ride.
Other apps don’t have this issue… I use the same HR monitor with several apps. Please fix… or let me use my Apple Watch for HR.
Best,
Michael