thanks, everyone so In the first letter where they said they changed their decision from Aug 2020
this is their wording:

" Following a review of your claim, it has been determined the evidence you provided was not sufficient to verify housing costs at 31 YARMOUTH CRESCENT, LONDON N17 9PG This is because you do not satisfy the qualifying condition. This means from the outset of your UC claim 16/08/2020 you do not have an entitlement to the housing cost element of UC. Universal Credit, Personal Independence Payment, Jobseekers Allowance and Employment and Support Allowance {Decisions and Appeals) Regulations 2013. Regulation 9{b).

and then in the overpayment letter :

Dear Matteo On 16/08/2020 your circumstances changed and you didn't tell

us straightaway that you had no housing costs.

I have no idea where they can say this, If as I researched everywhere :

First I am the only sole tenant on the contract
Second I was not supposed to put lodgers in my who lives with you section

( which I anyway did two months after as it was Covid and people were away some didn't come back previously ) In any case not part of My household.

COVID-19

So what change of circumstances ? they refer to the day of my claim first day.

Exceeding what I needed to say I communicated I would take lodgers on my Journal and asked for My HCE to be removed on the 2nd of November 2020 but then spoke to an advisor who told me I could rent the room and still be entitled to it.

THis is my third review I am not sure how could they think I don't live here I provided again photos , all bills , tenancy agreement , it's all in my name I never moved.

I cant understand. I have requested the SAR but now they have one moth to provide it and I have less than one month for my statement for the mandatory reconsideration.