There is a setting (right at the top of the list if you click on Menu | Setup) that says "Attempt Internet Weather Download While in Flight". If turned on, that is what you will get if you are connected to the internet and *don't* have an ADS-B connection going. That's a safety-of-flight issue and I think you should have that turned on if you don't have ADS-B.
But... let me note here that the FCC (not FAA) doesn't want you to have a cellular connection enabled while airborne. Tablets or phones. I don't believe many (any?) pilots are good about turning off their devices or putting them in airplane mode just prior to flight, but you're supposed to. But again: safety of flight. That trumps the FCC in IMHO.
Lastly, and this may only occur while *not* airborne: if you're connected to the internet iFly will do "housekeeping" chores. It will upload your settings to the iFly servers, and it will check to see if there are updates to the charts. (I know it does that regardless by checking expiration dates, but I think it also actively checks for updates if it has an internet connection -- I might be wrong about that.)