It sounds like maybe your HR and running thresholds in TP are off. Have they both been updated lately?
I find hrTSS and rTSS correlate pretty closely for flat runs, including flat treadmill runs. (For easy treadmill runs, I set my treadmill at 1% to compensate for the lack of wind resistance.)
For runs with any significant gain, rTSS is pretty much useless, so I go only by hrTSS.
I hope that helps.