Run 8908 was run for 1/2h at 1.5 uA instead of 3.0 uA, the ratio between the u and d reading stay the same pointing to a gain change (instead of a pedestal change).
Based on the end of run halog
Run 8907, 59 min, 3.0 uA, u3 reading 0.001042C, d3=0.01147 C, u3/d3=0.9
Run 8908, 23 min, 1.5 uA, u3 reading 0.00231 C, d3=0.002564 C, u3/d3=0.9
Run 8909, 62 min, 3.0 uA, u3 reading 0.0106 C, d3=0.0117 C, u3/d3=0.9