Is Millman's Theorem approach here correct?
Well, if it's of any help, I also get the same numbers as you. I calculated \$V_L\$ to be 4.7646 volts and I got a current magnitude of 1.0654 amps. I didn't bother to calculate the phase angles.

Is Millman's Theorem approach here correct?

Yes it is and I expect that the &quot;formal&quot; answer given has got some rounding errors. They also appear to be calculating \$V_L\$ to be exactly 5 volts and that is a mistake. I'd consider changing your text books if I were you because that's two questions you have delivered where the formal answer is either wrong or dubious.