Fenix 7 unpairing between activities

I have not seen your particular symptoms, but I did recently have Explore unpair everything (Fenix 6X Pro Sol, InReach Mini 2) after switching cell carriers. I switched services, and removed my physical SIM, and installed an eSIM, and when I launched Explore, it was as if I had installed the product from the store. I was running iOS 16.0.3 at the time on an iPhone 12 Pro.

I have noticed this too and have seen others report it.  This happens to me 1-2 times a month on iPhone 12 Pro Max running the latest iOS at the time.  Every time, both my Fenix 7 and InReach Mini 2 are unpaired and I have to re-pair each.  As you say, Connect is always still paired, and so sometimes I forget to ensure that the Explore app is also properly paired.

Because of the behavior, if I had to guess I'd say it's some kind of iOS Bluetooth app connection caching issue...like they're forgotten occasionally and a re-pairing is then required.  Not that hard to do, but a pain.

What's worse is, if I notice the problem after an activity, the activity sometimes doesn't properly sync to the Explore app when I re-pair.  It always syncs for me to the Connect app when I have internet connectivity, but I don't always have internet, so I count on the Explore app to keep my hiking/backpacking activities.

This happened to me again today after a hike and the Explore app did not sync the activity properly, so I worked on the problem a bit.  I used "Remove Device" to remove the Fenix device from the Explore app and then re-paired again, and when synced, I suddenly got a missing activity from Dec 12, 2022 (!) but not the missing one from today.  Removing the device again and re-pairing/re-syncing didn't help any further, so on a hunch, I deleted several of the oldest activities from the Fenix watch history - I had about 3 months worth, maybe 20-30 total?  After deleting several activities, removing the device, and then re-pairing & re-syncing, voila: my hiking activity from today properly synced.  So it looks like maybe there's some kind of data limit for the Explore app sync.

Hopefully, this will help someone at some point.

Recently I've noticed that the iOS Explore app unpairs much more often.  Both my fenix 7X and InReach Mini 2 are unpaired several times a week :-(

Not sure what's changed.

Try resetting both your iPhone and Fenix 7 to see if that resolves the issue. For the iPhone, you can do this by pressing and holding the power button and one of the volume buttons until the slider appears. Then, slide to power off and wait a few seconds before turning it back on. For the Fenix 7, you can do this by pressing and holding the power button until the device turns off, and then turning it back on.

That seems like an unlikely fix, I had the problem both before and after an iOS point update, as well, and I had exactly the same problem with the Garmin inreach mini 2.  But it appears maybe they did fix it on their end, as I have not seen the problem in several weeks now.