After a fresh install of Waydroid on my Pixel 3a, I had limited access to the navigation buttons at the bottom of the Android screen. I saw a post about this at:

https://forums.ubports.com/topic/7128/waydroid-on-fairphone-3-no-access-to-navigation-buttons-at-the-bottom-of-screen

and tried in a terminal:

waydroid prop set persist.waydroid.height_padding 65

on my Pixel 3a. I did not use "sudo".

This made the lower buttons clear the bottom of the screen just fine. Thanks for the tip!