It's a tricky one because exemption from 'bedroom tax' in Housing benefit, for reasons of 'major adaptations', is not a right - it's down to the individual council.
It isn't automatic, you have to apply for it; and it's more to do with cost considerations to the council than any rights that you have.
The idea of the 'bedroom tax' is to get people to move to smaller properties, thus freeing up the larger properties for those who will use all the bedrooms.
Where the council decides that the major adaptations needed to a smaller property
if you moved would be too costly for them then they can instead grant a Discretionary Housing Payment (DHP) to cover/waive the 'bedroom tax' payable and so let you stay in your already adapted property.
This government guidance applies, see:
Annex A: Benefit cap and Removal of the Spare Room Subsidy policy
https://www.gov.uk/government/public...manual#annex-b
(My highlighting and underlining)
So what you need to do is apply to the council for a DHP to cover the 'bedroom tax', on the grounds that if you did move to a smaller property then it would have to be adapted again, costing them more money than granting the DHP would cost.
I would suggest that you re-contact the 'Staying put Team' again for help applying for a DHP - after all what you want to do is stay put and that's their job.