I need help fixing the retirement block on my LES. S1, finance, MyPay, and retirement services are all no help. Can anyone help with this?

SGT (Join to see) no, you can opt into BRS for up to one year after you come on active duty. Once that year passes you are permanently with the Legacy plan. If you missed out on the opportunity then there is still a way to contact DFAS to enroll in BRS if you wanted to.
On an alternate note, if you aren't selected for CW4 and have to separate, you are qualified for statutory entitlement. If you choose, you can revert back to an NCO and stay for your retirement.

MAJ Ken Landgren I always do that before I leave a unit. Since every base is different and they each have their own "nuances", every time I PCS its like learning how to ride a bike again. I usually keep a big word document on the issues I encounter more than once and a solution on how to fix them and who to contact. Of course, with how fast things change in my field, and how quickly SOPs change, the information is pretty outdated within three years or so.

MAJ Ken Landgren is your DTS smart book still relevant with the new changes in DTS? If so, I'd like to get access to that. DTS has been a recurring issue in my unit for a lot of my guys.

SFC Boyd I gave the DTS Smart Book to the Army and don't know if they keep it updated. Just google DTS Smart Book. If you create an SOP it might be a feather in your cap. https://militarycac.com/files/DTS_SMART_BOOK.pdf Maybe you can use it for a test run to see if applicable changes have been made.