Rent a room relief & rental income for same property

I have a query regarding a situation where an individual received rental property income for their home while they were working abroad. Then, when they returned to the UK in September 2023, they rented out a room to a lodger while it was their main residence. My questions are: - Does the second period where rent was received from a lodger qualify for rent a room relief? - Would the first period be treated as a separate income source, or because it is rent received from the same property, would all of the income including that from the lodger be treated as normal rental income, and rent a room relief is not available for any of it? The individual at no point has been treated as non-UK resident because they were only abroad for 10 months. Thank you.