I can’t quite get my head around how the FX rate is calculated on buy and sell contract notes. I understand that the FX rate should be base FX rate + 45bps (or 0.45%).

Now these rates don’t make sense:

Base FX rate £1 = $1.2709 - FX rate £1 = $1.2643 (sell contract) - shouldn’t it be $1.2766??

Base FX rate £1 = $1.2561 - FX rate £1 = $1.2618 (buy contract) - shouldn’t it be $1.2504??

Can someone help with the math please?