First thing first: neither the Swivl App nor Swivl Cloud limits your recording time or prevents you from uploading long videos. For as long as your battery will hold out on your mobile device and your Swivl robot/marker(s) you'll find you will be able to upload videos that are several hours long in duration (though upload times to Swivl cloud will vary significantly on your wifi/data connection).
If you're experiencing an issue where a video "cuts off", it could be that your mobile device's internal storage is too low, thus affecting your ability to record a video longer than 'x' hours:minutes:seconds in the Swivl app. This issue would equally affect your ability to record videos using your phone or iPad's camera app. Videos recorded on your camera app outside of Swivl will also be limited.
Before recording, always check your Max Recording Time on your Swivl app, located at the top of your capture screen:
If you have very little recording time shown, you can free up space on your device by managing your storage.
For iOS devices, go to: Settings>>>General>>>iPhone/iPad Storage
From here, you can derive a better sense of where your internal storage is most used. You will need to free up space on your device (by switching to Cloud storage or deleting content) to improve your max recording time. This is also true for your general ability to record videos using your phone or iPad's camera app.
For Android devices, the process is relatively similar but appearance may differ depending on the specific device you have. In general: Settings>>>Storage is where you'll want to check on your specific Android device.