I've set the HR zones to be based on %HRR. However, for runs alone, the watch defaults to the original HR zones set using MaxHR alone. I don't have specific HR zones set up for runs. Please fix this bug, thanks!
Also most workarounds for this seem to be to set it through Garmin Connect web or something like that but now with all the settings on the watch those things are gone; even the Connect app just mirrors what's on the watch and it's not watch optimised. ♂️