Many commission based sales people are simply completing a transaction. This is an area where many investors are rightfully confused. If your advisor is dually eligible to both receive commissions and provide investment advice, which are they doing for you? If they are simply selling a product/platform and relying on the vendor to do all of the reviews and heavy lifting, then it is possible they are just serving in an arms length capacity.
For 401K, 403B & 457B plans, most retirement plan advisors are serving in a fiduciary capacity. There are some still in the small end of the marketplace that do not but it is difficult to justify your services if you are not providing independent advice. If your advisor is providing quarterly reports, assisting with the construction and amending of your investment policy statement, and continually providing guidance and advice to your trustees, then they are likely serving in a fiduciary capacity.
If they are showing up with the plan vendor and sitting on their hands while the vendor provides the evaluation and review piece, then you probably need to start looking for a new advisor. This is part 2 of the five part test and just about every retirement plan advisor worth a nickel is checking this second part of the test.