How did Bayambang lose its vast territories?

Question: How did Bayambang lose its vast territories, which reportedly included Camiling, Alcala, Santo Tomas, Bautista, Rosales, Paniqui, and Gerona?

So far, these are the only bits of information that can be found online:

1838: Camiling became independent of Bayambang. (Bayambang Quadricentennial book)

1875: A petition from the people of Dangla, a barrio of Bayambang, to become a separate town was granted with 11 cabecerias or barrios composing the new town which was later named Alcala. (Bayambang Quadricentennial book)

1901: Bautista, a sitio of Bayambang, became a separate town. (Bayambang Quadricentennial book)

1898, 1908: Santo Tomas, then called Aranggo, was part of Alcala in 1898 until its petition to become an independent town was granted in 1908. https://www.scribd.com/document/916919236/STO-TOMAS-pangasinan-history

1852: Rosales: Local history does not indicate Bayambang as the mother town.  "It is widely believed that the name Rosales came from the word rosal which is a name of a flower that was known to be abundant in the area. However, Spanish records revealed that Rosales was originally a ranchera founded by a pioneering Filipino named Nicolas Bañez. It was declared a pueblo in 1852. The place was named in honor of Don Antonio Rosales Liberal, a man noted for his rectitude, industry, and learning. He was also an Order of the Royal Audiencia in Manila and a Consejero de Filipinas en el Ministro de Ultramar (Secretary of Foreign Affairs) during that time." https://www.pangasinan.gov.ph/city-municipalities/rosales/

1712: Paniqui: Local history does not indicate Bayambang as the mother town. "Paniqui was originally part of Pangasinan and was established as a settlement in 1712 when a group led by Raymundo and Manuel Paragas arrived to expand the Christian faith. The name "Paniqui" is derived from the Ilocano word "pampaniki," meaning "bat," due to the presence of bats in the area. The town was initially located in a sitio called "Manggang Marikit," which was later moved several times due to safety concerns and flooding before settling in its current location in 1804. During the Spanish colonial era, Paniqui became a significant town, established as a parish in 1686 and later as a vicariate in 1718. The town faced challenges, including uprisings and natural disasters, which affected its development. Notably, in 1750, Sultan Ali Mudin was baptized in Paniqui, marking an important cultural event in the town's history." https://paniquitarlac.gov.ph/wp-content/uploads/2022/12/HISTORY%20BOOK%20of%20PANIQUI%201712-2012.pdf

1722: Gerona: "The history of the Municipality of Gerona can be traced back to the reign of the Spaniards when the Dominican Missionaries in the Philippines started to propagate the Catholic faith in the whole archipelago in 1704. The Dominicans placed the Vicar of Malanguey (sic) (now Bayambang, Pangasinan) to be in charge of the mission of converting the local inhabitants of “Paontalon” (original name of Gerona) to become Catholics. In 1722, Paontalon was recognized as a small village and became part of the Municipality of Paniqui then under the Province of Pangasinan. Reference: https://geronatarlac.gov.ph/town-history/