Earlier this week there was also that behavior. A MICH offset by itself doesn't help. When the is an SR TY misalignment of 2 urad, then the sideband get misbalanced, and the MICH offset restores the sideband balancing. With SR TY misaligned, without a MICH offset, when the dark fringe offset for locking the OMC is put it the power on B1p increases by a factor ~3 and becomes too high. Adding a MICH offset when SR TY is misaligned removes that problem. So at the moment SR TY misalignment and MICH offset are a combined package where both need to be put in at the same time to help, one of them on its own doesn't help, and actually makes some things significantly worse.

The SR TX misalignment doesn't seem to have that issue of affecting the sideband balancing. So maybe a MICH offset is not needed in that case, and just reducing temporarily the SR TX loop gain between CARM NULL 1F and LN3 would be enough to make that idea of SR TX misalignment work in a systematic way.

Note that the sideband balancing changes when staying in CARM NULL 1F for one hour, so what may be true for 15 minutes after reaching CARM NULL 1F, may be no longer true one hour after reaching CARM NULL 1F.