I did read that what the source of the word Palestinians id Philistines. About which I know next to nothing. I posted this a few weeks ago. This condensed report may be of some help...
You can search for the terms ...
palestine roman governor renamed hadrian
and find other sources that go into more detail. Bottom line is that after a Jewish revolt, the Roman governor wanted to not only subdue Judea, but he wanted to take away their heritage - including the name of their country. He asked his historians for the strongest historical enemy of the Jews and the answer came back as "The Philistines." The Philistines of The Old Testament did not have an Arab background; rather it is believed they were from the island of Crete or possibly Macedonia. THey tormented Judah and Israel as recorded in the book of Judges, I Kings, II Kings, I Chronicles, and II Chronicles.
So Hadrian forced the name "Philistia" onto the Jewish people. That name is Latin for, "Land of the Philistines."
This is why I find it so upsetting when I hear Pastors or other Christians refer to God's Chosen/Promised Land as Palestine, only to sound cool and edgy. They are actually blaspheming the name applied to God's promised land.
This false name was used during the centuries following and even during the late 1800s and into the mid-1900s even the few Jews who lived in the area had adopted the name. The current newspaper named, "The Jerusalem Post" was called, "The Palestinian Post" and The Palestinian Symphony was later renamed, The Jerusalem Symphony.
The Egyptian, Arafat, invented a history by conflating this make-believe history even to the point that he and his brother were "Palestinians."
By the way, this tact was advised by a Madison Ave public relations firm hired by Arafat during the 1960s. They told him that to gain the world's sympathy, he had to invent a history for Palestine. It worked after being supported by the media and academic fraudsters around the world.
As now deceased and Messianic Rabbi Zola Levitt often said, There is no history of Palestinian art, currency, literature, poetry, music, language, ... etc.
It's all a fabrication supported by the Jew-hating media. The Truth About 'Palestine'—Then and Now.
https://cbnisrael.org/2021/10/21/the-truth-about-palestine-then-and-now/