In case you assume that your dispatching real time campaign is not running as intended, please follow the steps from the checklist below to get to the root of the problem as quickly as possible:
Check frequency capping on the campaign level (Campaigns → Edit → Cappings) to ensure the number of messages user is allowed to receive per specific time frame is set up correctly. There you can also disable campaign dispatching to users who have already received a message in another campaign(s) of your choice.
See if "This is a transactional campaign" mode (Campaigns → Edit → Campaign setup) is turned on. If yes, users will receive messages disregarding frequency cappings on either campaign level or global level.
Examine the profiles of affected users by looking for specific users in the segment or building the segment including specific user(s) in User segments section. Please be aware that deleting cookies on the used device may affect the assignment of user to a segment.
Assess the user journey of your campaign: it should have wait times built in between the steps if the rules in steps consider any time frames. For example, if you look for cart abandonment in the last hour, you have to make sure that the system waits for one hour after user completes the last step of the journey (leaves the checkout page), otherwise the message will be triggered immediately.
Check whether there are similar or duplicated campaigns with the same message. In case there are, user can be triggered by the same message while fulfilling any of two (or more) user journeys. Also, if you test the campaign on your own by copying it, make sure your message is different from the original one, otherwise you will not know exactly which campaign has triggered the message you get.