Okay, so I posted about a week ago about DS2 (9 weeks) waking up fussing 5 minutes into a nap/bedtime EVERY time after he falls asleep. I think I figured it out - I watched him one day while he slept and he has a VERY strong twitch about 3-5 minutes into sleeping and sometimes he sleeps through it and sometimes it's so strong he can't. I'm assuming this is part of his moro reflex. He is swaddled very tightly in a Miracle blanket and sometimes I use a regular swaddling blanket to change it up but it doesn't seem to have any rhyme or reason to when the sudden twitch really bothers him. When does this reflex start to disappear, or when do the "sleep twitches" start to bother them less? He can put himself to sleep - he sleeps up to 8 hours his first stretch at night! However it's that initial "twitch" that unsettles him and scares him. I guess I was really confused because up until about 2 weeks ago he would quietly settle himself to sleep without issue and it's just in the last 2-3 weeks this twitch has really affected him getting to sleep and staying asleep.
I don't know if it's the same thing or not, but my husband does this every night...his parents say he's done it since he was a baby. Apparently FIL does it too.
I do this quite a bit, it is most likely to happen if it is not very dark and quiet, but it's not a single noise that jolts me. More just like my brain doesn't think it's safe to go to sleep or something. If I really feel like it's bed time it doesn't happen. Dunno if it will work, but I would try to develop some kind of little calming ritual to do before bed. Good luck!