Oven keeps warm after OFF

Oven v1

It keeps sometimes warm after baking. I bake it night. Let the oven cool down for 30 Minutes.

After that the oven to luke warm, bread goes in - next morning the bread is pretty warm. The rack is bare touchable >50°

Update: it’s the round bottom plate that is hot (>100°) whenever it’s connected to power.

How to fix that?

Maybe related: oven sometimes (1:5) triggers the current leakage switch when in 100% steam mode.