Seattle Forrest

I use Android and don't know iOS well enough to go deep into the details. But your phone should have some kind of list of apps with the permissions you allow them. The answer is almost certainly there. This comes up fairly often on r/Garmin and that seems to usually be the solution. I hope it helps. 🙂

Edit to add: the "heat acclimation" is ... you're probably not missing much there. But correctly adjusted VO2max is probably worth having if you use that feature or the training summary based on it.

Iride01 

Maybe I should just leave this thread alone, but today I may have figured out something somewhat related to an issue the OP referenced.

I to generally will get a "high aerobic shortage" when it's not giving me a cue about something else in the Garmin phone app. Today I was actually on Garmin Connects website comparing some things with RWGPS which is what I normally rely on for post ride data review.

I noticed that the times in HR Zones of GC were way off compared to RWGPS. Garmin Connect had my max HR at 210 bpm instead of the more correct 175. So that means I'd never get into the high aerobic or even anaerobic zones.

So possibly the OP needs to check their max HR setting in GC. I think mine got messed up a short while back when my strap went bad and I had to get another. Possibly my Edge 530 ask me about whether I wanted to record a new max HR as it does some other things. But if it did, I just mindlessly accepted that so I could get on to seeing the other things I look at on my Edge immediately before I dismount and go in the house.