Right now, you should definitely use AS 3.5.2 or higher when building multiplatform with Anrdoid. The Android IDE plugin contains very, very important bug fixes, which will make your life easier!
Bugs: I am always filing them on YouTrack only. JetBrains Team will give further instructions then ☺️
Example:
https://youtrack.jetbrains.com/issue/KT-35016