"They (the Palestinian) have the title to their land, so why...

"They (the Palestinian) have the title to their land, so why can't they return home after the war."

Looks they haven't and the Jordanians who have extensive pre 1948 records don't want to share!

Similarly, Palestinians concerned with the complex question of 1948 refugee rights and compensation/reparations for property left behind in what became Israel have begun searching for documentary support of their land claims.
From 1953-1964, the United Nations Conciliation Commission for Palestine (UNCCP) used microfilms of mandate land registers donated to it by the British — one source of such information — to determine the extent of Palestinian property in Israel. Individual Palestinians have requested copies of UNCCP documents over the years to support their claims to future compensation. Additionally, the UN provided microfilmed copies of these records to Egypt, Jordan and the Palestine Liberation Organization (PLO) in the 1970s and 1980s.
The PLO and the PA, however, have been unable to access the PLO’s copy of the films for use in the final status talks with Israel. They are stored in Damascus and under the control of a rejectionist faction. One solution could be the use of Jordan’s records relating to Palestine, a subject already introduced in PA-Jordanian talks in early 1996. Jordan’s records relating to land in Palestine are extensive, and include not only the West Bank documents mentioned above but Ottoman and British registers for all of Palestine. The Jordanians also possess other mandate-era records as well as a microfilmed copy of the same British registers that the UNCCP holds. Jordan obtained its copy in 1952 from a Palestinian employee of the former Palestine land department who had hidden the films in Jerusalem during the 1948 fighting. Jordan later bought microfilms from the UNCCP itself as well. But Jordan has refused to grant information on land holdings from its pre-1948 Palestinian holdings to the public, a policy it reiterated in December 1996. [7]

https://merip.org/1997/03/documenting-land-ownership-in-the-palestinian-authority/