Cannot find device when scan

[rhampong]

SmuView-0.0.6-git-7050317-x86_64-installer : Win 10. I select Tekpower TP 4000ZC and scan for device with a BT90_EPC multimeter connected. Serial port Com port interface. This worked successfully on my desktop and laptop (win 8.1) many times. I did not consistently use the same usb port.
Then over the course of a few days testing, I had problems finding TP 4000ZC consistently when scanning. And now I cannot find the device anymore.
I tried uninstalling and reinstalling Smuview with no success.

Thanks RHP

ver 0.0.6 totally does not work anymore. Seems as though there is built-in timer to stop being able to scan for device.
I uninstalled and then installed the stable version SmuView-0.0.5-x86_64-installer on my laptop and desktop. SMUview scanned and found my device without hesitation. I will continue testing and changing usb port so see if it is stable.