You show app_source as the stanza for your props.conf. Is that reflective of the source or sourcetype of your data? If the former, it should be source::app_source instead, as per props.conf:
<spec> can be:
1. <sourcetype>, the source type of an event.
2. host::<host>, where <host> is the host, or host-matching pattern, for an
event.
3. source::<source>, where <source> is the source, or source-matching
pattern, for an event.
4. rule::<rulename>, where <rulename> is a unique name of a source type
classification rule.
5. delayedrule::<rulename>, where <rulename> is a unique name of a delayed
source type classification rule.
These are only considered as a last resort
before generating a new source type based on the
source seen.
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