What’s the error? Did you try deactivating everything but Jetpack and MapPress?
That’s the problem: There is not any kind of error or warning visible in the log 🙁
That is the affected website: https://freisenbrucher.de with Mappress and Jetpack activated. Map should be visible by “<span class=”mh-widget-title-inner”>Freisenbrucher Orte</span>”. Can you please take a look?