The two terms are used interchangeably, and both lose their meaning as a result.
Propaganda targets belief
Propaganda tries to change what a person believes. It needs repetition, reach and time, and it is visible: the message is open and the source is usually known.
Hybrid influence targets behaviour
Hybrid influence does not persuade. It creates conditions: doubt, fatigue, a sense that nothing can be checked. The goal is not belief but the end of checking.
That is why such campaigns rarely carry a single message. They push several contradictory explanations of the same event, and each finds its own audience.