My leasehold flat has a leaking skylight and my property management expect me to pay for all of the repair

For context, i purchased a leasehold flat around 3 years ago. A block of offices had been converted into flats and the skylights that form a triangular shaped roof structure above my kitchen were there from the original office block.

7 days ago they began to leak with storm bebert. I let the property management company know and they said that i am responsible for the fix (£2,000). I said that they form part of the roof and were already there when i purchased the flat. They do not open and form a roof structure.

Am i liable to the claim. It says in my leasehold that i am responsible for the windows and their frames but i am not sure that these are technically windows as they do not open and they fork part of the roof structure.

The leasehold does not have anything specific about skylights.

What should i do?