Windows 10 Game DVR not pre-recording full specified time

[Windows Central Question]

So I have it set to record the last thirty seconds. Which is usually good enough to capture something funny that happened or an epic moment in game. However, when I hit my "record that" Shortcut, it records 99% of the time NOT the full 30s that happened. For instance while playing gears of war 4, i frequently noted that i captured only 14s. Around there. Just recently recorded some footage first using ShadowPlay pre-record, then using MSI afterburner pre-record and both recorded a full 30s video. But when i used my game DVR it recorded only 28s. almost 30s lol but not quiet. Any ideas? Am i the only one experiencing this? I DO make an effort to turn off other DVR's before using a different one so i ONLY have 1 active at a time.