I think a more precise observation is that when law enforcement is more heavily scrutinized, they crack down harder. This isn't police "confusing" journalists and protesters like you are implying.

Example:

Federal Judge Restricts Portland Police Interactions With Journalists, Observers (July)

https://www.opb.org/news/article/federal-judge-portland-poli...

Portland journalist arrested while clearly displaying his credentials (August)

https://www.kgw.com/article/news/local/portland-journalist-a...