After Effects exports materials with a frame less

AE strange behaviour noticed.

Suppose I have an map animation exported from Google Earth Studio - an mp4 of 1920 by 1080 with 30 fps - and I want to add some shape and text animation on it in Ae, so I import the mp4 file, create a sequence with it (with the same properties as the file), then make my shapes and texts above it and then exprort them as a separate mov file with an alpha channel. So both mp4 and mov files have the same resolution and framerate, hence they must be of the same length.

But once I import these into Premiere Pro for the further work I always see the same problem - the mov is one frame less

Always.

This is the props for the mov:

Type: QuickTime Movie
File Size: 62,53 MB
Image Size: 1920 x 1080
Frame Rate: 30,00
Total Duration: 00:00:17:01

And this is for the mp4:

Type: MPEG Movie
File Size: 21,14 MB
Image Size: 1920 x 1080
Frame Rate: 30,00
Total Duration: 00:00:17:02

Why does this happen?

And this is the Project duration: 

So somehow a sequence - created via dragging the mp4 file as long as 00:00:17:02 - always gets a frame less duration.