Something must have happened while I was working on the WFS path, and when I looked at the beat note before returning to the corner station the beat note was -40dbm. (Was -10dbm before).
Changing temperature had almost no effect. Measured the IR power from Prometheus and the fiber, both were good.
Started realigning the path and eventually got back to -16dbm at about 40MHz. Still big, though not as big as before.
Now the laser temperature is 35.6 degree C (was 33.7 before), though to me both of these temperature look perfectly fine.