Issues about the limesdr's calibration setting

hi,
i meet some strange manner with qspectrumanalyzer and soapy-power backend.
at first, this program’s frequency-tuning procedure is very slow, with about 0.3s of one reset-stream() call. if we enable the cacheCalibrations switch to true, then the tuning time is reduced to 0.01s. but, sadlly news is the qspectrumanalyzer’s output will keep-no-change(same as before) until about 60s later. what’s the matter i met?
thanks.