If you have a retirement plan with more than 100 participants, you probably have a plan audit (if you have more than 120 participants, you do). Like with any plan providers, there a lot of great auditors out there and some not so good.
So if you’re auditor brings up issues dealing with plan compliance, confirm those findings with plan providers and/or ERISA attorneys because auditors maybe great at accounting, they aren’t legal experts. I have an advisor-client (cheap plug here) who asks me to confirm what the auditors are saying on the compliance end and occasionally, they’re wrong and their answers could lead to compliance headaches especially where the Department of Labor and Internal Revenue Service are concerned.