Hi,
From what I understand, you're using the "actions as a button" option of the mass action to add a button to your products listing.
As the name of this option implies, when you use this button, it will run the actions of the mass action on the selected products. Filters and triggers will be ignored.
It's like when you click the "process" button of the mass action and the triggers of the mass action are ignored.
So this result is normal.
Similarly, it's normal that when you have both a CSV export and a display action, only the CSV export is done.
A CSV export action run manually implies the download of the generated file to the browser of the current user.
And in HTTP, the browser makes a request to the server and then waits for the response from the server.
If the server sends HTML in the response, then the browser displays it.
If the server sends a download, then the browser runs the download interface.
It's not possible to return both HTML and a download in a HTTP response.
So you get this because of the limitations of HTTP and we can't do anything about it.
Similarly, you can't have several CSV export actions in the same mass action as HTTP only accepts 1 download per HTTP response.
So this result is normal too.