While looking at locklosses today, Vicky and I noticed that after we reach NLN, the MC2/IM4 TRANS power increases 0.1 to 0.5%.  

Daniel helped look at this and we expect the ISS to change to keep the power out of the IMC constant, but the power after the IMC on IM4 TRANS (not centered) changes ~1% too. Everything downstream of the ISS AOM sees this change plot, something is seeing a slow ~1hour thermalization.

• Plot Nov 13th, MC2 TRANS increases 0.5%
• Plot Nov 9th, MC2 TRANS increases 0.35%
• Plot September 2nd, MC2 TRANS increases 0.1%
• Plot September 11th, MC2 TRANS increases 0.2% (IFO DOWN for 6 hours before)

The same signals at LLO are show a similar amount of noise (slightly more in the MC2_TRANS) but no thermalization drift, but LLO has a lot less IFO thermalization.