Now, I'm sweeping K1:IMC-SERVO_NPRO_TEMP_BIAS_OFFSET from 1 to 0 to find the range where the mode-hop is not occured. According to the medm setting of the BIAS_OFFSET, since we can change the value from 0 to 1 I decided to sweep the value in this range. In order to keep PMC lock, the sweep speed is very slow so it will take 2.8 hours (10000 secs) to finish the scan. 

Today, I left PMC in this state. So please do not touch PMC, especially the K1:IMC-SERVO_NPRO_TEMP_BIAS filter bank and the k1ctr3 PC until 20:00 JST without any contact to me.