Employer questioning Occupational Health recommendation for full remote work (UK, reasonable adjustment) - is this normal?

I work in England in a consultancy role that can be performed fully remotely. My employer introduced a policy last year requiring staff to attend the office three days per week. Prior to COVID, I worked five days a week in the office. At the time I found the environment extremely draining and struggled with concentration, fatigue, and stress, but I didn’t understand why and assumed that was just something I had to tolerate.

During COVID we moved fully remote and I found that I could work consistently without those issues. My concentration improved, I was less fatigued, and there was no impact on my productivity or collaboration. We remained largely remote for a long period after that. When the three-day office policy was introduced last year, I struggled with it and did not attend three days regularly. The policy has not been strictly enforced, so in practice I have been going roughly once every couple of weeks. Even with that limited attendance, I still experience significant cognitive fatigue, distraction, and exhaustion after being in the office, often needing the rest of the day and sometimes the weekend to recover.

I was recently diagnosed with Autism Spectrum Disorder and submitted a request to work fully remotely as a reasonable adjustment due to sensory hypersensitivity in open-plan environments (noise, movement, lighting, temperature changes, etc.). My employer referred me to Occupational Health. The OH clinician confirmed they had seen medical documentation, stated that my condition falls under the Equality Act, and recommended that I continue working remotely to prevent symptoms being exacerbated by attending the office. The report described this as a permanent advisory.

After this, HR contacted me and said the report does not contain enough explanation for why I cannot attend the office and that it reads more like I simply don’t want to go in. They said they cannot move forward without more detail. They offered either another OH appointment or for me to answer a long list of questions myself.

Some of the questions make me uncomfortable because they seem framed in a way that looks like they are trying to demonstrate I can attend rather than assess the adjustment. For example, they asked how I managed office attendance before the diagnosis, how many weeks I have attended three days, whether adjusted start and finish times would allow me to attend, whether flexible days could increase attendance, whether the commute is really the issue, what adjustments in the office could be put in place to support attendance, how often “flare ups” occur, and whether the condition has worsened in the last 6–12 months. They also asked whether I had the condition when I joined the business and how I managed it then.

I had specifically asked Occupational Health not to include detailed personal medical information in the report because I prefer to keep those details private and understood that OH acts as a buffer. It feels like I am now being asked to provide the detailed explanation directly myself.

Is this normal following an Occupational Health recommendation? Are they allowed to effectively say the OH advice is not detailed enough and ask me to justify everything again? I’m also unsure how much detail I’m expected to provide personally versus what should come from Occupational Health. I’m trying to cooperate in good faith, but the tone and structure of the questions makes me concerned that they are building a case to refuse full remote working rather than genuinely assessing the adjustment.