What’s you noise floor? A high noise floor will indicate external interference on the DL (customer side). Download LTE Discovery, Network Cell Info or My Mobile Coverage apps to your Android device and that way you can record the PCIs and the RSRP-RSI and SNR. Thatd give you an Idea where to start looking. If it’s external you need to check if your other sectors are creating it (you can turn them off) or use an Spec A and scan your channels. External interference is one of the hardest things to troubleshoot/find but it’s doable. Hope this helps.