Failure to Implement Employee Deferral Election-- QNEC in excess of 50%?

The employer changed payroll providers at the beginning of 2023 and for some unknown reason the deferral election of one participant was not properly implemented and for 8 months no deferral was withheld from the participant's weekly payroll.  The employer, however, continued to deposit the participant's elected amount.  We are working on how to properly correct.  My questions are this:

1.  Am I correct that this would meet the definition of Failure to implement an employee election found in Appendix A of the EPCRS Rev Proc 2021-30?

2.  If this does meet EPCRS definition above, then correction would be QNEC equal to 50% of the amount provided by the employee on the deferral election.   Since the employer has actually deposited an amount greater than 50% of the required QNEC, is it permissible to leave the excess in the Plan for this participant?

Thanks

Perhaps the mistake is an opposite direction.

Your description of the facts suggests the participant had made an elective-deferral election, and the employer/administrator implemented the election by paying money to the plan.

Is the plan whole for the elective-deferral election the participant had made?

Is the mistake that the employer failed to segregate the elective-deferral amounts from the employee’s wages and paid the employee more wages than she was entitled to?

If so, the employer might consider how much (if any) of the mistakenly paid wages the employer seeks to recover from its employee. In that, the employer might recover amounts slowly, or find ways to adjust the employee’s wages. Perhaps the mistake might have been an acceleration of what otherwise might have been the employee’s next wage increase?

This is not advice to anyone.

1.  Seems like this would be an Failure to Implement

2.  I believe you can do more than a 50% QNEC....

I think I lean to the fix of:  IF the dollars submitted to the plan were "correct", I would shift the money from the Deferral source to QNEC and move along.  Earnings are done and aren't a factor because the "correct" amount was invested into the right funds.  This also alleviates the employer trying to recoup funds from the employee.  To be clear, I am suggesting a 100% QNEC.  

Similar issue discussed here: