Difference between max daily heart rate and max heart rate of an activity

it's a known issue. Garmin needs to fix it, at least in connect.
has been discussed before on the forums.

Thanks - do you by chance have a link to the previous discussions? All my searches lead to heart rate not being properly recorded but unfortunately not this specific comparison topic. 

Just guessing. Probably the value from the activity is instantaneous while for daily summary it’s just a 1-minute average.

So unless you keep the maximum HR value for at least a minute, on the daily report it’s going to be just a little lower than that.

probably.

but who cares, it should be consistent. As a wearer, the HR did go up more than what the app displays in the central dashboard. If it didn't go for a whole minute, shouldn't matter.

Yes, the all-day graph shows the min and max HR held for at least a minute. All day HR and HR during an activity are measuring different concepts - usefulness in measuring what they are supposed to is more appropriate than consistency.

Thanks.
To check if I understand your statement correctly: If I would hold my maximum HR value in an activity for >1min it would show up in the all-day max field?

Just found this myself. Was this meant to be fixed, or is it working as intended? 

Seems a bit silly, Max for the day should be Max, not average max or anything else. If I sit on the couch all day at 60bpm, then sprint up and down the stairs hitting a HR of 180bpm for 30 seconds, my max HR for the day will only be 60bpm?!?

edit: just read the help file in GCM, it only says the highest observed HR for the day, nothing about sustained for 1min etc?

support.garmin.com/.../

Thanks - they should probably change the Help File in GCM because it doesn’t explain it anywhere close to the same way. 

No. Your heart rate would have been above some point between 60 and 180 for at least a minute. At the very least, it would be 61.