Totally normal CGM behavior and normal to be worried about it. Have you heard of presoaking? From the glossary topic:
Pre-soak: the practice of inserting a new CGM sensor up to 24 hrs before the current sensor session expires, allowing it to acclimate to the body before activation. This is intended to ameliorate erratic readings in the first 24 hrs of a new sensor session.
Here’s a topic where people discuss ways to handle to first hours-day results with a G7.