So what did I do wrong????
Threshold test - Garmin 955, hrm-pro plus Threshold test link
Started a run, chose guided test, warmed up and got directions. After some time the watch said, "Threshold detected 163 bpm - cool down recommended". I slow jogged home and stopped the run as I do with all runs and saved it.
I have auto detect threshold "ON"
I did not get prompted for changing zones or anything.
When I check reports/running/lactate threshold it says, "You have no data for this time period."
I have no idea about what I should have done differently.... :-/