FAILURE IN SERVER /n_set Node 1364 not found

I have this code:

(

// Random notes from lydian scale
p = Pxrand([64,66,68,70,71, 73,74,76],inf).asStream;
// ordered sequence of durations
q = Pseq([1,2,0.5], inf).asStream;
t = Task({
	loop({
		x.release(2);
		x = Synth(\default, [freq: p.value.midicps]);
		q.value.wait;
	});
});

t.start;
)

And i get the error next:

-> a Task
FAILURE IN SERVER /n_set Node 1364 not found

The code seems to work correctly. Does anyone have any idea what is going on? I am on a Mac M1.

Perhaps clear x before starting the loop.

hjh