DD 4.5 months has been happily exclusively BFing for pretty much all her life and is suddenly now taking 3-4 suck/swallows, unlatching and crying, then repeating this process 2-3 times. Most of the time it's only on the first breast (doesn't matter which) and then she just resumes as normal on the second one, but sometimes it'll be both.

She recently got a Rhino brace for hip dysplasia so its possible that has affected it, but I'm vague about whether or not this was happening before the brace. Any other causes?