The steering performed by the APS at the beginning of the run caused a somewhat significant change in the beam profile delivered by the mirrors to the sample. As the XBPM is very sensitive to the beam profile, the automated feedback has not been functional this run.
Continued consultation with Instrumentation Technologies and Dectris has suggested that the profile change was enough that the XBPM needs to be re-calibrated. A quick test of this on Feb 18 showed this to be the case.
Recalibration will be attempted on Feb 23, after which the beam feedback should be functional.