Lord jagannath being pleased with Ramanujacarya; instructed Him to go to Mayapur to see the Leela of Lord Chaitanya Mahaprabhu(Leela was unmenifest at that time).
So Ramanujacarya leaving His disciples there went to Navadvip and Lord revealed Himself there to Ramanujacarya.
Also Lord jagannath instructed Ramanujacarya to keep the divinity of Lord Chaitanya hidden.
These are all constructions of some Gaudiya vaishnavas. Sri Ramanujacharya left His body in 1137 CE and Sri Chaitanya was born in 1534 CE. Ramanujacharya established the Emar Math in Puri (which Sri Chaitanya used to visit when the Jagannath temple remained closed before the annual rathayatra festival). Ramanuja was dissatisfied with the way Sri Jagannathdeva's worship is done and he intended to change it. But Sri Jagannath was pleased with whatever method the pandas were adopting. He mystically shifted Sri Ramanujacharya to the Kurmakshetra (which is far away from Puri) overnight.
This is mentioned in the authentic biographies of Sri Ramanujacharya including the beautiful one written by Swami Ramakrishnananda, a great scholar and a direct disciple of Sri Ramakrishna.
By the way, none of the acharyas of the four famous Vaishnava sampradayas, namely - Ramanuja, Vallabha, Nimbarka and Madhwa accept Sri Chaitanyadeva as an incarnation of God so far as my knowledge goes. And no famous Vaishnava bengali saints outside the Gaudiya Vaishnava sampradaya accept Mayapur as the birthplace of Sri Chaitanya - As per the biography of the siddha Vaishnava saints Srila Radharaman Charandas Babaji and Srila Ramdas Babaji by Abha Sarkar, the actual birthplace of Sri Chaitanyadeva has been discovered by them at Navadwip and a temple was build there long ago. (I dont have the book with me now and so I am not able to provide reference details.)
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