engine fluctuates from 3000 to 5000rpm

[Transcat E-Tec 200]

hello members, I'm new here. This is an evinrude etec 200ho it runs beautifully at idle to 2600rpm once I throttle up it will race then fall. Once we hit 5000rpm it misses and falls to 3000rpm. I changed all fuel filters and one leaking hose. The problem did not get fixed. I'm noticing a very loud squeal coming out of the fuel pump. What do you think? Added observation while on dry dock running prop disengaged it runs at 5000rpm but at 5500 it drops to 3000. Is the fuel pump not providing enough fuel for high rpms or is the computer acting up.

Thanks!

[Transcat E-Tec 200]

More info it's new fuel and new oil.

[boats.net]

Need to have fuel pressure checked to see if maintaining pressure at high speed. May need to get a computer download to look for any fault codes.