TemperedLB work max goes up

[lifflander]

Describe the bug
This should be impossible given the locking mechanism.

vt: [0] (t) TemperedLB: TemperedLB::loadStatsHandler: trial=0 iter=15 Load[max=1920.10 min=1088.01 avg=1510.42 pole=20.01 imb=0.2712]  Work[max=1921.63 min=1089.64 avg=1510.70 imb=0.2720]
vt: [0] (t) TemperedLB: i=1952.0009799879995 in=1921.6329122109998 rel=3.796008472124953, tol=0.1
vt: [0] (t) TemperedLB: TemperedLB::rejectionStatsHandler: n_transfers=2806 n_unhomed_blocks=11497 n_rejected=0 rejection_rate=0.0%, total_cycle_locks=992
vt: [0] (t) TemperedLB: TemperedLB::maxIterTime: 0.005287369000000042
vt: [0] (t) TemperedLB: TemperedLB::loadStatsHandler: trial=0 iter=16 Load[max=1920.10 min=1108.02 avg=1510.42 pole=20.01 imb=0.2712]  Work[max=1937.22 min=1120.00 avg=1510.70 imb=0.2823]
vt: [0] (t) TemperedLB: i=1952.0007049779992 in=1937.2169400699995 rel=1.8479706134999674, tol=0.1
vt: [0] (t) TemperedLB: TemperedLB::rejectionStatsHandler: n_transfers=2716 n_unhomed_blocks=11499 n_rejected=0 rejection_rate=0.0%, total_cycle_locks=986
vt: [0] (t) TemperedLB: TemperedLB::maxIterTime: 0.005253587000000004
vt: [0] (t) TemperedLB: TemperedLB::loadStatsHandler: trial=0 iter=17 Load[max=1920.10 min=1108.02 avg=1510.42 pole=20.01 imb=0.2712]  Work[max=1921.63 min=1120.00 avg=1510.70 imb=0.2720]
vt: [0] (t) TemperedLB: i=1952.000681319999 in=1921.6327137410005 rel=3.79599594737482, tol=0.1