Couldn't spot anything specific in your file.
Check the Timeslider-RMB > PlaybackSpeed > .. if it is set to Realtime, then it might skip some frames to approach desired fps. If you want to see the animation i real-time, you might wish to Playblast, otherwise set the PlaybackSpeed to PlayEveryFrameMaxRealTime.
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Maya2019.1 @ Windows10 & GeForce GTX1080Ti
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