Ndef in pattern kills the effects chain

Questions
1

Hello, I’ve previously asked a question about how to create a pattern of ndefs.
This got answered but now i stumbled to a problem, that creating a pattern with this set method, silences the initiated reverb of the ndef.

I think my problem becomes clear when playing the code, so the reverb can be heard when first initiating the ndef part. Once you execute the pbind part, the reverb gets stopped abruptly. How to fix it, so the reverb gets recognized to the fullest?

Here is the code:

//create a simple synthdef
(
SynthDef(\sn,{arg amp=1, out=0;
	var sig;
	sig = SinOsc.ar(440)*Line.ar(1,0,0.1,doneAction:2);
	Out.ar(out,sig*amp);
}
).add
)
//create a Ndef of the previous synthdef
//and how a single shot is supposed to sound like
(
Ndef(\snn).clear;
Ndef(\snn).play;
Ndef(\snn).prime(\sn);
Ndef(\snn).put(100,\filter -> {arg in; FreeVerb.ar(in,0.7,1)});
Ndef(\snn).put(0,Ndef(\snn).source,0);
)
//create a pattern
(
Ndef(\snn).put(101, \xset -> Pbind(
	\amp, Pseq([0.3,0],inf),
	\freq, Pif(Pkey(\amp) > 0, 1, \rest),
	\dur, Pseq([0.1,1.9],inf),
))
)
//stopping or playing the pattern
Ndef(\snn).stop;
Ndef(\snn).play;

Thank you very much.