What everyone already said is completely true.
Unwashed hair gets dirty, not knotted. Dirty hair gets oily and greasy. This prevents knotting and slows down and process.
Dreadlocks are an ever-changing process. Even when mature, they still change. I have one that I could get a bead on for years. Then one day, after I washed, I could no longer get the bead on. It got wider. And mine are 6 years old.
Dreadlocks do not form over night, no matter what starter method is used. Back combing and TnR only help your hair and scalp get used to where you want the sections to be. It is not a means to "create" locks.
So them unraveling is completely natural, and should happen. If you are very lucky, they won't untangle all the way. But if they do, don't stress about it. This needs to happen so that your hairs can actually start knotting. Just pushing them all backwards does not create knots. it just creates kinky hair. This kinky hair is easier to knot, but are not dreadlocks unto themselves.
So wash them, separate them when they start to snag hold of other locks nearby, and go enjoy life. You don't want to have to feel afraid to go outside if it's raining, or cross the street if a sprinkler is on someones lawn. Living in fear of all water is not a way to live.