For some reason, I can't die in survival mode now (XBONE)

Have been playing in Survival for months, but recently when I get killed in combat I don't really die. I end up sitting on the ground looking injured for a moment, like your companions do when waiting for you to stimpack them. Then after a moment I'm back up and in full health. I have mixed feelings about this since it breaks the immersion but it's also nice to not have to reload from the last time I found a bed every time I get jumped by a pack of gunners or radscorps. But I have no idea why it started doing this. Can't tell if it's from some mod I installed (I read the descriptions pretty thoroughly and never saw this "feature" mentioned, but then most of them are horribly documented to begin with), an update Beth did, or some other bug. Anyone else run into this?