The video controls (play, skip forward, skip back, etc.) are displayed over top of the operating system soft buttons for app switch, home, and back in portrait mode of VLC.
This issue showed up for me when I moved the video files on my device from internal storage to the sd card. I tried copying a file back to internal storage and the option to delete was only available on that file.
When playing a video, I frequently press the "Fit" icon in the lower right when I am fast forwarding multiple times. I think this can easily be fixed by putting a setting in the preferences for the "Fit Mode". The user can choose Best Fit, Fit Horizontal, Fit Vertical, Fill, 16:9...