The 学生 of 大学生、中学生、小学生 is only “xuéshēng”. other "xuésheng" and “xuéshēng”. Sometimes the 学生 of 小学生 is "xuésheng" too.but this means young pupil or young student.

we do not pay much attention to this pronunciation in normal life .so~ take it easy~~

The official pronunciation is xuéshēng. Saying "xuésheng" sounds like your are speaking dialect

Depends on dialect. Xue2sheng is typical in northern China. I think xue2sheng1 is typical in Taiwan, could be wrong. Either way, it doesn’t matter too much. Both are correct.

学生xuè sheng, this pinyin is correct. 生sheng here should be neutral tone.