For many months the Lactate Threshold update (sync from watch to connect) was broken for all watches and Garmin claimed they fixed it ~1 month ago with the update to the 14.13 version. forums.garmin.com/.../lactate-threshold-recorded-on-255-but-it-is-not-updating-in-garmin-connect
My last LTH detected during a workout is from January, my friend hasn't seen a new LTH pace or hr detected for ~3 months now ... all of this could be we are just in plateau or Garmin fixed the sync problem by not detecting new LTH values anymore.
So have you seen Lactate Threshold Updates detected in the last 4-6 weeks? Did they only show up on your watch or did they also get synced to Garmin Connect?