On Monday, I found that the cavity remote locking was not working properly. Matteo told me that somehow the treshold for lock acquisition was changed last week.

I put it back to the original value of -0.5 V and now it seems to work quite good.

I also found the the transmission was not stable despite the dithering was engaged. The situation improveed after I increased the gain. (Pic 1) 

Current values:

INPUT ATTENUATION: 2.9

GAIN: 5.7