Why is mega backdoor roth contribution showing as income?

Context: I made contribution to mega-backdoor roth last year i.e.

I made $X non-Roth after-tax contributions to my 401(k). I did Roth in-plan conversion and immediately converted the money to the Roth account within the plan. My contributions didn't earn any interest income as I immediately converted $X to my Roth account

 

Question: Why is the entire mega-backdoor contribution showing up as income in turbotax? This was after tax money and there was "0" interest earned before conversion. If the mega-roth contribution is showing up as income, am i not being double taxed on the after-tax money on which i have already paid tax?

 

Am i doing anything wrong?