The BS was showing some excess motion. I think I've fixed it. Order of operations:

• The DC PIT bias from previous ASS runs was at ~500, I zeroed this and aligned the BS to be centered on its oplev QPD with DC alignment sliders
• I squished the gold box cables. This changed the alignment slightly, and brought the UR voltage back to a normal value. Excess motion still existed
• I found that the the C1:SUS-BS_LRSEN filter had HOLD OUTPUT enabled. I turned it off. All seems well. 

I'm not sure how this might have gotten switched on...