iPhone 6 - video-taking issues?

Hi there, I've been having this problem intermittently since I got my iPhone 6 when it first came out. I have a 64 gb iPhone 6, iOS is up to date to the latest version (8.1.3) and I have almost 30 gb still free. When I take a video, the video will sometimes automatically stop shooting after 10 seconds. For the first time ever, today it cut itself off after 1 second.

Has anyone else had this issue? At first I thought it only happened when I swiped up to access the camera from the lock screen, but today I got the issue when i accessed the camera from my home screen. I can't seem to find any rhyme or reason for it. There have been times I've been able to take videos without issue - in fact, two nights ago I captured nearly a minute-long video of my younger daughter without issue.

Any insight anyone can lend would be greatly appreciated. I was trying to take videos of my older daughter to send to her grandmother and I had to stop because the camera wasn't cooperating.

Many thanks in advance for any help or insight anyone can lend!