Whole safari app zooming in

I have noticed that when I open up the safari app it sometimes zooms in by itself. Not just the website but the whole app. This has only occurred on my iPad. It zooms in so much that it partially cuts out the plus sign on the top right of the app. If I try to zoom out it doesn’t fix it so the only thing that works is to close and reopen the app. I was wondering if anyone knows why or how this happens or if someone else has experienced this? Thank you for reading