(Google translation)
In previous versions of Vegas Pro, information on ACID loops such as beats, BPM and root note was displayed in the Explorer window. This information is not observed now in version 15 and is very important to previously identify a loop in musical montages with ACID files. In the images we see how it is shown in Vegas Pro 10, but not in 15.
The appropriate settings have been made to perfectly recognize these files such as Import audio at project tempo, time format in Measures & Beats and snap to grid.
I think it appropriate to report if it is a bug.