whole feed content in wprss

Hi folks,
on my page I offer the custom rss feed (https://www.oekologische-plattform.de/wprss). If I import this feed using “another rss” on smartphone (android app from https://f-droid.org/), some feeds (for example from https://www.labournet.de/feed/) include the whole content of the imported article from labournet or other sources.
So I would to limit the content which is offered by wprss.
How to achieve this?
Thank you in advance

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