Android navigation buttons disappear

[onchov]

When I start the app, the three Android nav buttons disappear. To temporarily bring them back (for example if I want to close the app or switch apps) I have to swipe down from the top, which is not convenient and adds an unnecessary step to the process. Can we have an option to keep the nav buttons visible at all times, please?

The problem exists for Android 11 on Samsung S9. On an older Android phone I have, the nav buttons don't disappear like this.

Thank you.