Is the Qibla that was determined by compass correct, or must the precise location of the Kaaba be determined and faced, especially after some brothers found online that the precise location of the Kaaba differs by 37 degrees to the left?

If the builder investigated the direction of the Qibla when placing the mihrab of the mosque, and then it became certain that the mihrab did not hit its direction, it is obligatory to reorient it towards the Qibla. The past prayers are valid due to the excuse of ijtihad (independent reasoning), based on the saying of Ibn Qudama that if someone who exercised ijtihad prayed towards a certain direction and then it became clear to him that he was mistaken, he is not required to repeat the prayer. However, if the deviation is slight and does not go outside the general direction of the Kaaba, then there is no need to change it, because what is obligatory is facing the general direction, not the exact عين (eye/point), based on His (Allah's) saying: {So turn your face toward Al-Masjid Al-Haram} [Al-Baqarah: 144], and the Prophet’s (peace be upon him) saying: "What is between the East and the West is a Qibla."