Fuel unit failure P3043 Mechanical Issue

Hello

I have an issue sometimes, does not matter what the fuel level is, once 8 of 10 the fuel unit is good, after sending P3043 mechanical failure, specially if I need to restart the car in few minutes. Is it a controller or a fuel pump unit failure?

5Q0919050AD is the fuel unit but I do not find an original one just replacements.. which one is the best? Wanted to buy VDO, Pierburg but it shows Fispa, Sidat, Meat & Doria, Hoffer, Hitachi and Vika.. I do not know either.

Thank you