If anyone is currently paired on your app and if someone is currently viewing the experiment, you could be switching a user back and forth between the variations. Keeping in mind, this can only happen on dev builds on devices and devices that were previously paired or currently paired.
A best practice to QA in this scenario is to force a device into a variation through the variation switcher to QA.
Here, a user will be put into the chosen variation permanently until you switch the user back. You can find your device in device settings or through User Insights and can read more about the Variation Switcher here.