I'm NOT licensed in Tennessee, but when this happens to my clients in California, somebody at a higher level in the state HR office heard you returned then panicked that the modified position went way beyond what the physician's report precluded.
In California -- and I suspect in Tenn -- if the worker gets re-injured or new injuries by being sent to job duties the employer knew the worker couldn't perform safely, BIG Penalties apply (we call it Serious & Willful Misconduct of the Employer here, increases the Permanent Disability award by 50%).
I'D APPLY FOR UNEMPLOYMENT INSURANCE IMMEDIATELY (hope as a state worker you are eligible for Unemployment Insurance).... in Calif., that forces the employer to find the permanently-modified job for you or lay you off right away instead of letting you dangle for 5 weeks while they have meetings about you.
Tennessee has a person you can email about this... shorten this to you were working a permanently-modified position for 6 hours when you were told to leave and not permitted to work, by what form can you appeal this decision: EMAIL firstname.lastname@example.org
Of course, with a state job in the balance, you'd be most wise to hire expert counsel... most charge nothing until the claim concludes, and it could mean your job and your retirement.
It sounds like they are in the process of pushing you out the door. A friendly TN Attorney may be able to sort out your situation with a written inquiry.
We offer general concepts, but you should give ALL your facts to a licensed Attorney in your state before you RELY upon any legal advice.
They would do it because they are the State and they want someone without any injury or anyone that may be injured. Sounds like common law retailation to me, but I would need more information. I would certainly recommend that you file for UI compensation through the TDLWD inasmuch as I would like to see them fight benefits being paid and it can serve as a good informal discovery tool.
I am not your attorney nor is any answer I may provide legal advice. You may contact me directly for legal advice only if you are a resident of Tennessee insofar as I only practice in Tennessee.