I added the notch filters at FM3 of ETMX_TM_LOCK_L filter bank as shown in fig1.
After engaging notch filter, the peak height starts to decrease, so the notch filter seems to work well.

I also modified the guardian so that the FM3 is engaged after locking PRFPMI with DC readout (fig2).
In addition, I changed DOWN state so that the FM3 is turned off when the lockloss happens (fig3).