When I put in a second data-only SIM into my dual-SIM Android 7.1 phone, the text message notifications that Garmin Connect sends to my vivoactive say "SIM 1" (the primary/only SIM texts come in on) instead of the actual body of the text. By contrast, my car also links via Bluetooth to my phone and doesn't display/say "SIM 1" when it get texts in this dual-sim configuration. So, I think it has something to do with how Garmin Connect is parsing texts.
Anyone else seen and reported this behavior?