I can't say that that happens to me. Though I haven't hidden in a locker for a long time, mostly under or behind things, I changed my tactics over time. I'll have to hide in a locker again, just to check. It could depend on the level in single player or the map challenge mode. When Stompy gets pissed passed a pint, he will kill us fast.
I did notice a problem with hiding in closets and lockers a long time ago, before I got the mod. The first times I played the first DLC map, the one with Ransome, I also constantly died when I hid in closets and lockers. First I thought it was a glitch but then I saw what I was doing. I was pressing the prompts in the wrong order. I first leaned back and then I tried to hold my breath, instead of the other way around. When I first lean back, I can't hold my breath and then I die. When I followed the prompts correctly, things were back to normal. So maybe that's it?
Another tip, when you're in closets and lockers, there's still a way for Stompy to not notice and zero in on you. First, don't bring up the motion tracker, he can hear it, if not even see the light a bit. Second, if you lean left or right, so as to avoid the line of sight with Stompy, he almost certainly won't come. If you can't see him, he can't see you. This last bit really helps, I suggest you try it.