Since nothing received from Support e-mail or on this forum (as of yet) I started my own investigation. Looking on: https://apkpure.com/kasa-for-mobile/com.tplink.kasa_android I could see that...

This is happening to me as well....on two different phones.... it takes id/pwd and returns to app but Home shows guest logged in and anything requiring access when logged in (i.e. remote control)...