Different banner sizes in test mode and production mode

If you have a long horizontal screen, the banner will appear smaller in test mode, but larger in production mode.
Why is this?
It overshadows the content in unexpected ways.
Is there a solution or a way to modify the banner size programmatically?

The difference was not between test and production, but between Unity and the actual device.

my ads are loading in test, but in live app, there is no banner ads fill.