Values of RSRP and SINR to suspect external noise/ interference in the sector?

Move a little bit around, left and right. Is SINR still 1 dB?

No relation between ANR and this interference.

These apps didn’t give correct SINR value sometimes.

Need to check SINR through DT tool.

I think the issue is related to external interference:
Check if any close airports, Army area.
Also maybe it is a HW issue.

Noted. Thank you All!

Check AQM, DRX settings and smart pre allocation.

I have this observation (for Huawei) that Smart Pre Allocation stop working when user exceed certain threshold so in that case we rely solely on DRX.

AQM also help in reducing latency.
Or you can also tune pdcpdiscardtimer but better to go with AQM.

Check RSSI KPI as well to confirm external interference with poor SINR.

Check if NBR rsrp is within 1~3 db difference and having high utilization