I am not sure whether this is indeed a bug since the report name is called QSO report, however the data fields make provision for the SNR values to be displayed.
When a PING is done to a station, the Ping field is ticked in the QSO log report (shown below), however, no SNR values are recorded. See the highlighted image below.
It would be fantastic if the PING SNR values could also be reported here.
Most likely a unsuccessful ping. Meaning it was a ping that was not completed - only connection was made but no SNR was received.