Packet RSSI variating on LoRa packet length

I have a test setup where I have two devices communicating by LoRa under ideal conditions.
If I transmit and receive longer LoRa packets with at least 20byte of payload the packet RSSI register has reliable values (about 120). But as soon as I have very short packet with a payload of 2byte the packet RSSI register seems to get invalid, the values are then 174 and with the equation given within the datasheet that leads to 34dBm which is much to high. (The packet SNR register has values from 34 to 42 binary, which is in all cases positive.)
Does somebody know if the packet RSSI generation has problems with small LoRa packets?

A previous answer I received from Semtech:

Typically PktRssi is averaged quite significantly, to give a more precise result in the end. For shorter packets, and at strong signal conditions, it may be that the averaging filter is intialized at “0”, and therefore skewing the result. It shouldn’t be a big issue, as typically 1. in real application, -28 dBm isn’t the type of Rx power observed in a system, 2. typically this type of result indicated “a lot of signal”, and therefore the actual indication of RSSI isn’t so relevant in a system optimization.

Best regards

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