Location Page Featured Image “full-size”

Hilfe – Help
I′m just beginnung with event-calender, but will publish a lot of events, and like to solve the problem before. If i open a single Event-Page the Featured Image (Post-Thumnail oder Beitragsbild) is blown up to the full size – it looks terrible !!! – how can i delete the “featured-image” at this place or give him a correct size 600 x 400 px. two lines later i used the format-possebilities … it runs – but can′t find any way to design the part above ???
Same problem with the location-page “location-image” is full-size.

For test if i delete code with inspector … it looks good ?

Prefered answers in german
Thx for your help

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