Preview in Service Studio Version 11.53.16 / Build 61265 seems to be broken. All blocks get the following style assigned which is causing the issue:
Hi @Ferdinand Brandl, thank you for reporting the issue. Can you please test with the latest stable GA version? 11.53.16 61323, you can find it here.
Thank you, @Marcelo Penas ! The issue has been resolved.
See the following post for a workaround: https://www.outsystems.com/forums/discussion/81467/why-does-screens-blocks-now-have-padding-in-service-studio/