I have an (almost) 2 month old and notice she also has problems with my letdown but only when she is tired. She does the same thing, pull off, get's mad and then bobs back on. I believe that she just wants to suck but doesn't want a lot of milk when she is really tired. She only does this when tired. Is your LO similar? Is this behavior occur all of the time or only when she is tired? I am 100% sure that this LO does not have reflux because I have 2 boys who DID have reflux and her behavior isn't anything that of what the boys had.