Fuel pump prime at key on

Hi guys
Since new my emublack on V2 software “blips” the fuel pump for a split second at key on/power on, regardless of the time settings in the software and if I invert the output the fuel pump runs fine.

When I load V3 firmware the fuel pump prime runs correctly for whatever time I set it for

Curious as to why this is so, haven’t been able to find a reason