You have an active campaign with a wait step in the flow but you noticed leads aren't coming out of that wait step, or they seem to be repeating the wait step.
The most common reason for this is adding a flow step above the wait step. If you add a flow step above a wait step the position of the wait step is changed. Example your flow steps were a total of 4 with the wait step being the 3rd flow step but you add a flow step above the wait step making it the 4th step in a total of 5 flow steps. This means when the leads come out of the wait step they end up going right back into the wait step.
The best solution is to not add/modify flows with wait steps on active campaigns, but for more information and options, see this article: Editing Campaign Flow with Members in Wait Steps .