The snap to the left - Skip silence is checked off. You may want to uncheck that and see how that goes. I don't use that and have not had any missing voice. Then again, maybe you have something else going on.
Also, max recording time at 30 minutes is pretty long. That's PER transmission. So if there's a stuck Mic or something it'll hold on to that channel/talkgroup for 30 minutes and then continue. I set mine to 1 minute.
My recording prepend buffer is .5 (half a second).