How to trace a faulty LTE UE/Modem on U2020

4G LTE
1

Hi experts;

i have a high PS drop on a 4G cell during the day low trafic (out of busy hours) and i suspected a faulty UE/Modem on that area,
so i need to know what kind of tarces i need to lunch (S1 interface or X2 or Cell trace) & how to confirm the issue based on trace signaling messages,

Thanks in advance