Mirny doesn't behave as expected

Hi all,

I am starting to use Mirny again after first testing it six months ago when we received the new Artiq crate.
The code I am using is the following (it is the same as I used for testing):

from artiq.experiment import *
class GHz_Test(EnvExperiment):
def build(self):
self.setattr_device("core")
self.setattr_device("mirny0_cpld")
self.setattr_device("mirny0_ch0")

    self.setattr_argument("freq", 
                          NumberValue(1*GHz, ndecimals=6, unit="GHz", min=1*GHz, max=4*GHz)
                          )
    self.setattr_argument("attenuation",
                          NumberValue(10*dB, unit='dB', scale=dB, min=0*dB, max=31*dB),
                          )
@kernel
def run(self):
    self.core.reset()
    self.mirny0_ch0.cpld.init()                            
    self.mirny0_ch0.init()   
    delay(10*ms)             
    self.mirny0_ch0.set_att(self.attenuation) 					 
    self.mirny0_ch0.sw.on()	
    self.mirny0_ch0.set_frequency(self.freq)
    delay(1*s) 						                                      
    self.mirny0_ch0.sw.off()

The problem is that the signal does not switch off, and I can see the outputted RF also on another channel which wasn't even switched on in the first place and has a red light.
Have you ever had a similar problem and/or can you tell me what the issue might be?

Best,
Claudia