hi @Don_Jiang welcome to Zwift forums.
Is your Garmin Edge computer turned on while you’re Zwifting? If so, it might be stealing the BLE signal before Zwift has a chance to find it Would you try leaving the Garmin computer off while you’re Zwifting and see if that’s the problem?
Hi @shooj Thank you for your kind reply, I have tried using the ZWIFT with the EDGE130 OFF and TURNED ON, both cannot. So frustrated 
Hope it works… I don’t know what and how will it. I tried connecting using my iPhone also did not work. Problem is, I cannot see my Garmin Speed and Cadence Sensor using the Bluetooth Search on either my Phone or my iPad. my EDGE130 see them immediately.
Same Problem, used to work on my iPhone 8, then just stopped. Put in new battery’s, turned off all other bluetooth devices and still says no signal. It picks the Speed and Cadence sensors up, but my avatar doesn’t move. Worked on an old iPhone 6s that hasn’t been updated with newer IOS.
Serious problem cause I’m close to cancelling my account.
@Warren_Auld
Newer versions of Apple OS’es (iOS, TVOS, watchOS) require you give apps permissions to access the Bluetooth radio, or they won’t be able to see Bluetooth signals.
Please confirm that’s done on your iPhone 8?
Thanks for the reply. Yip, double checked, it’s all on. trying to post a pic of my settings but this forum won’t let me.
I’ve reinstalled the app several times.
@Warren_Auld
I trust you’ve read through the various issues & their solutions upstream?
The only other thing I can thing of is if you have Zwift installed on more than one device, and are logged in to the same account simultaneously on more than one at a time. Install Zwift on only one device to avoid any of the issues that come from concurrent logged-in devices.