I have no idea what kind of electric pump you installed, but I clipped this quote from an instruction sheet for the Holley Blue:

"The pump is designed to push fuel and not designed to suck fuel out of the tank. It needs to be gravity-fed or if it’s pulling from the top of the tank, it needs to develop a siphon feed to the pump."

So basically Holley is saying you got the expected result from your install.

Priming is absolutely necessary for most electric pumps, and running the pump on a dry line is likely your only problem.