Sequence Start Frame issue

Just getting the hang of Sequences, so I’m sure this is a really noobish question and I’m sorry.
I’ve made an keyframe animation that I like, it works perfectly and plays when I tell it to through blueprints. However, somewhere in my workflow it accidently sets the “idle frame” or it’s first frame to someplace in the middle of the animation.
I found no way of solving this, so I remade the entire animation (not that much work, but still), made it work like I wanted to and a while later, it happened again. It is now starting on the wrong frame, only to jump back to frame one if played.
It’s sort of hard to explain, so sorry if it’s somwhat confusing, but what am I doing wrong here?

So, it seems to have disappeared now that I’ve fiddled with it a bit more. It MIGHT be connected to the “Ignores Origin Shifting” tickbox, but I can’t reproduce it regardless.
Still curious to know what it was, if anyone knows.