Sheila and I reducded the IMC input power from 61W back to 60W. As we haven't been very stable today, it's possible this might help.
It was increased in 80295 in an attmept to avoid PIs. No IFO retuning was done with this setting This didn't help the PIs and the ETMY ring heater was increased in 80320 which successfully avoided the PI locklosses.