On the most recent update of the Android app, the Assistant interface is broken for me.
Specifically, if you either use the icon to go directly to Assistant, or go to it via the four square icon on Kagi Search, it opens and you can make queries, but you cannot cannot select any of the menu items at the top. So you cannot show your query history, cannot create a new query (just continue the current one) and you can't open the hamburger menu.

It looks kind of off too, with that little gap you can see in the image between the phone status bar at the top and the Kagi logo below.
In the prior versions, that gap wasn't there and the buttons worked fine.
I am using a Pixel 7 running GrapheneOS, so maybe it isn't all Android devices.