On your conducted test, it indicates that pump and valves are working fine. IMO also most probable cause is pump voltage... Every motor has high starting current due to inertia and transient… When voltage is very low caused by required low rpm (required fuel flow rate on ignition) most likely for long loaded fuel line requires a little increase in power.

Another probable cause since it’s new is pump motor. Brush and bushing are still tight. Since startup voltage is very low, just impending, slightly increase in voltage will solve the problem then after certain runtime restore the original voltage settings to prevent high starting temp. Otherwise, let the pump run for a few moment until it start easily.

Hope would help.