Garmin Connect Mobile 3.13.0.1 update - notifications don't go away

How does the app have permissions to read SMS when unchecking the permission to read SMS? What other permissions or personal data does this app access that I do not know about?

What other permissions or personal data does this app access..

That's in the app permissions:

Read phone status and identity
Take pictures and videos
Approximate location (network based)
Precise location (GPS and network based)
Read call log
Read contacts
Write call log
Read calendar events plus confidential information
Read, modify or delete the contents of your USB storage
Find accounts on your device
Read Google service configuration
Download files without notification
Full network access
Google Play license check
Receive data from internet
View network connections
Access Bluetooth settings
Pair with Bluetooth devices
Run at startup
Draw over other apps
Control vibration
Prevent phone from sleeping
Send sticky broadcast

(this is list from an old GCM version and more may have been added recently)

Things like SMS, contacts, calendar access etc are necessary because the app sends notifications from the phone to the Garmin device. That data is not sent to Garmin. Notifications, (missed) call notifications, SMS notifications, and calendar still work even when there is no internet access on the phone. The app needs location access on the phone to retrieve weather information for your area.

And of course the app accesses personal information on your Garmin device, uploads it (activity timeline, heartrate, GPS tracks, device serial numbers etc), and removes some of the data from your device after uploading.

That's in the app permissions:

<snip>

And of course the app accesses personal information on your Garmin device, uploads it (activity timeline, heartrate, GPS tracks, device serial numbers etc), and removes some of the data from your device after uploading.

His point/question was more of: how is the app still somehow reading SMS messages even though he's removed permission for it to do so. It makes him wary that it might be reading other things he doesn't want it to.

I'm wondering if this bug will ever be squashed personally.

This has been fixed in version 3.15. Tested myself

Seems to be working here on 3.15 too, Lollipop on an LG G4, though I only just installed it. The previous version would work at first, only to show unremovable notifications later. So, I'll report back if that happens.