The legal duties and responsibilities re a Leaseholder’s Information Form

I am trying to ascertain the area and extent of the responsibility for the completion and assessment of this document and not finding it easy. The Leaseholders Information Form (LIF) is completed by a vendor and so far as I understand matters must answer honestly and has a duty to inform their solicitor of any matter that changes.

We have a LIF (transaction completed in January) where the presence of a boiler is referred to under “warranties existing” but the questions re condition and claims are blank. We now know that a significant leak occurred two days after we viewed the property, the management agent informed the Landlord of the event and the LIF was completed (albeit with gaps) three days later and making no reference to the event or it’s being handled by the rapidly renewed service contract.

Qs1,2,3 What are the legal duties owed by the vendor and two conveyancing solicitors?

Many thanks

David