Hi Yusyuan,
I've figured out the problem - you have declared an ion mobility value for the precursor, good, but there is no resolving power set so the ion mobility filter width is zero and no signal gets picked up. Try the settings in the picture and reimport the data, it should be fine.
As it happens I am working in this code area at the moment, and had already made the change to use all IM values instead of none when no resolving power is provided - this seems like a reasonable use case if you're interested in exploring the use of IMS vs not using IMS. (Also you won't have to check the "Use spectral library..." box to activate the resolving power control.)
Thanks for bringing this to our attention!
Brian