Long-term disability denied after 2 years of payments - "maximum medical improvement" what does that even mean?

I have been receiving long-term disability payments from Unum for my back condition (two herniated discs, confirmed by MRI, affecting L4-L5 and L5-S1) for almost 2 years. Last month I got a letter saying my claim is being terminated because I've reached "maximum medical improvement" and their Functional Capacity Evaluation shows I can perform sedentary work.

The problem: I am a construction project manager. My job requires me to physically walk job sites, climb ladders, and be on my feet for extended periods. A "sedentary work" capacity doesn't describe anything close to what my job actually requires. My own doctor has consistently said I cannot return to my occupation. Their FCE says I can sit at a desk.

There are a few things that seem off to me. The FCE was done by a physical therapist they hired (not my doctor), it lasted only 4 hours, and she's never been to a construction job site in her life. The letter also mentions my policy has an "own occupation" definition for the first 24 months and then switches to "any occupation" - and of course they're terminating at almost exactly 24 months.

Is this a coincidence? Has anyone dealt with this specific situation with Unum? I feel like I need an attorney at this point.