Retirement tax questions

It should have been done thru the payroll system and been reported on correctly on the W-2 ... you are NOT self employed... you are an employee of the corporation.   So did the box 1 of the W-2 reflect the correct amount of wages ?  If not then you need to issue a corrected W-2 to fix not only box 1 but the box 12 entry as well.

And it should not be on the K-1 at all but the company match does reduce the company earnings which in turn reduces the K-1 passthru amounts.