RS boosting & RSSI/RSRP relationship

Hi all.
I have a modem setup with capturing my local cells KPI such as RSSI, RSRP RSRQ.

I have noticed that different composite carriers are received by my modem (SIM7600) with various different values of RSSI-RSRP. They typically range between 25dB and 35dB delta.

I tested this difference over a 30dB RSSI range (with a programmable attenuator) and the difference values are quite linear.
I also tested various composite carrier bandwidths, which does not really correlate to these differences.

I am now wondering if these differences are due to the carriers having different RS boosting values.

If this is the case, it would be quite useful to deduce the RS boosting values from this basic KPI delta measurement RSSI minus RSRP (dBm)

Comments please!
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