The right side of my iPhone display changes by itself in standby mode

I’m using an iPhone 16 & ios 18.5. As I set my phone on the side with magnetic power supplied I have the left side set with an analog clock and the right side with my calendar. However, when I vibrate my night stand to activate the display, the analog clock displays properly but my calendar is replaced by an add from Apple to use the journal app. How can I keep it on my calendar and stop the add from showing?

[Re-Titled by Moderator]

Original Title: Right side of display, while in standby mode, changes the display by itself.