Issue in [[post_excerpt]]

Hi Brian,
hope, You are well.

I have a very strange issue:
Using manual excerpt Noptin appends the title of an feed, subscribed by RebelCode’s “WP RSS Aggregator”.

The original Excerpt is:

Wir beantragen, […] aktiven Mitgliedern.

The campaign is defined as:

post_title
post_excerpt
read_more_buttonganzen Artikel lesen/read_more_button

But the received Email contains:

Antrag an den Parteivorstand
Wir beantragen, […] aktiven Mitgliedern.
? Wie das Z?hlen von Bienen, Mücken, Schmetterlingen gegen das Insektensterben
hilft <https://www.oekologische-plattform.de/?post_type=wprss_feed_item&p=238594&gt;
ganzen Artikel lesen
<https://www.oekologische-plattform.de/2020/08/antrag-an-den-parteivorstand/&gt;

As in the page the excerpt is shown acceptably I think it should be an Noptin issue.
Please could You correct this.

Thank You

The page I need help with: [log in to see the link]