kint with query monitor causes functions to run twice

I’m not sure if this is a kint problem or a Query Monitor problem so I’m submitting to both:

For a test I have created a simple plugin that just stores an incrementing variable in $_SESSION and dumps the value before and after incrementing. Here’s the simple code:

function myStartSession() {
	
	if(!session_id()) {
		session_start();
	}

	d($_SESSION['iteration']);
	$_SESSION['iteration'] += 1;
	d($_SESSION['iteration']);
}
add_action('init', 'myStartSession');

The expected behavior is that on every page refresh the starting value of “iteration” will be the previous end value of “iteration”. e.g.

val = 1
val = 2
refresh page
val = 2
val = 3
refresh page
val = 3
val = 4

When I have kint + debug bar active it all works as expected. But when I have kint + query monitor active then WP behaves like it runs the functions twice, with one of the runs being kinda invisible (no output). So instead of the above expected result I get something like:

val = 1
val = 2
refresh page
val = 3
val = 4
refresh page
val = 5
val = 6

I discovered this behavior because another plugin that I use writes an activity log to the db. With kint + query monitor active I always get duplicate entries into the database. But without that combination everything is fine.

Here’s a screencast that walks through what I’m seeing: